The Internet - web1.muirfield-h.schools.nsw.edu.auweb1.muirfield-h.schools.nsw.edu.au/technology/resources/IST/...An intranet is a private network that uses a similar interface to

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Syllabus outcomes5.2.1 Describes and applies problem-solving processes when

creating solutions.

5.2.2 Designs, produces and evaluates appropriate solutions to arange of challenging problems.

5.2.3 Critically analyses decision-making processes in a range ofinformation and software solutions.

OverviewThis chapter will develop your understanding of the Internet andintranets. It examines the uses of the Internet, Internet softwareand types of protocols used on the Internet. You will learn aboutthe World Web Wide (www) and developing a website.

The Internetand websitedevelopment

The Internetand websitedevelopment

313 ISTech Chapt 12.3pp 23/9/04 12:36 PM Page 261

262 HI Tech: In format ion and Software Techno logy

12. 1 The Internet andintranetsThe Internet (the ‘Net’) is a connected set of networks using theTCP/IP standard. It links millions of computers all around theworld. The Internet provides instant access to information such asnews, weather reports, sports scores, share prices and educationalmaterial. It also provides services such as sending messages, banking,shopping, playing games and listening to music. People access theInternet in their homes, at school, at work or even at the beach.

Establishing a connection to the Internet involves one of threebasic types of connections: direct connection, dial-up connectionand broadband connection. Direct connection is through a LANand is used in many schools and organisations. Users are notrequired to dial-in, files are stored on their computer and responsetime is fast. Dial-up connections require a modem and telephoneline. A typical connection is much slower and often less reliablethan a direct connection. Modems are capable of delivering data at56 Kbps or faster. Broadband connection uses a higher bandwidththan a dial-up connection and is much faster. The bandwidth is thecapacity of the channel or transmission media. Broadband users arenot required to dial-in and the Internet is available all the time.Both broadband and dial-up connection are delivered using normaltelephone lines, a direct connection uses a dedicated dataconnection.

Accessing the Internet requires an ISP. An Internet serviceprovider (ISP) is an organisation that provides access to the Internetfor a fee. There are hundreds of ISPs in Australia, such as TelstraBigPond, OptusNet and Ozemail (see Figure 12.1). Each ISP offersa different level of service and support for a specified charge.

Figure 12.1 BigPond is an Internet service provider


26312 The Internet and webs i te deve lopment

Historical perspectiveEven though the history of the Internet is relatively short it hasundergone many significant developments.

ARPANET (Advanced Research Projects Agency Network) was thebasis of the Internet. It was established in 1969 by the US Departmentof Defence. The aim of ARPANET was to allow scientists at differentlocations to share information and protect against a nuclear attack.The ARPANET was built with no central authority because thatwould make the entire network vulnerable to attack.

Telenet was the first commercial version of ARPANET and waslaunched in 1974. In 1979 Usenet was established with a focus onnewsgroups. Newsgroups allowed users to conduct discussions onparticular topics. In 1981 BITNET (Because It’s Time Network)connected IBM mainframes around the educational community andthe world to provide mail services. A link (gateway) was provided toconnect BITNET to ARPANET.

The Internet arrived in 1982 when ARPANET adopted the TCP/IPstandard. The number of hosts on the Internet reached one thousandin 1984. The domain naming system (DNS) was first implementedin 1984. In 1986, the National Science Foundation (NSF) agreed tobe the ‘backbone’ for the US Internet service. It connected its hugenetwork (NSFnet) to the Internet and provided fivesupercomputers to service the increasing volume of traffic.

A friendly user-interface to the Internet started in 1990. A simplemenu system called gopher was developed to access files andinformation for the University of Minnesota. HTTP (HyperTextTransfer Protocol) was developed by Tim Berners-Lee forembedding links in text. In 1991 the World Wide Web (or Web) wasintroduced using this HTTP protocol. It has changed the appearanceof the Internet. Mosaic was developed by Marc Andreessen in 1993.It was the first graphical browser to display hypertext documents.

IntranetAn intranet is a private network that uses a similar interface to theWeb. It is essentially a smaller version of the Internet that existswithin an organisation. Intranets support email, newsgroups, filetransfer, web publishing and are accessible to users by a browser.The main purpose of an intranet is to share information andcomputing resources among the members of an organisation. Theinformation may be staff news, product information, telephonedirectories, policies, employee manuals and calendars. This information

Lit 5.1

Interactive



can be displayed in a web page using a similar method to that usedon the Internet.

Extranet is an intranet that is accessible to customers, suppliersor others outside the organisation. It provides information such asproduct descriptions, frequently asked questions, warranties andhow to contact customer service. Organisations are attempting tomake extranets easy to use and a source of relevant information.

Internet addressesEach computerconnected to theInternet has aunique addresscalled an IP address(Internet Protocoladdress). Most IPaddresses use fourbytes (32 bits)grouped in four 8-bit segments,separated by a fullstop (period). Forexample, the IPaddress forMicrosoft is

205.188.200.58. IP addresses are difficult for people to understand,so another addressing system is used based on a domain name.

A domain name is the address of a specific computer on theInternet. Domain names are translated into IP addresses. Domainnames are easier for people to remember than IP addresses as theyare based on natural languages. A domain name consists of a numberof separate parts. Each part is separated by a full stop and is called adomain. For example, the domain name ‘www.hi.com.au’:• ‘www’ stands for World Wide Web• ‘hi’ is the name of the specific computer• ‘com’ is the organisational domain• ‘au’ is the geographical domain.Organisational domains include ‘edu’ for education, ‘mil’ formilitary, ‘gov’ for government, ‘com’ for commercial, and ‘org’ fornon-profit organisations. The United States is the only countrywithout a geographical domain, although some US sites haveadopted ‘us’ as the geographical domain. Geographical domains

Figure 12.2 An Internet address is used to locate information on the Web



include ‘au’ for Australia, ‘uk’ for United Kingdom, ‘fr’ for France,and ‘ca’ for Canada.

A URL (Uniform Resource Locator, pronounced ‘you-are-el’) isthe address of a file or resource on the Web. It is usually in lowercase in a single unbroken line, with no spaces, such as:http://www.hi.com.au/heinneman/default.htm

There are three parts to a URL:• Protocol—indicates access to a particular resource on the Web.

For most cases the protocol will be http://. It allows access toweb pages based on hypertext.

• Domain name—address of the specific computer where theresource is located such as www.hi.com.au. The domain name isinterchangeable with the IP address.

• File path—full path to the file to be retrieved. It may be a simplefile name or a directory path, such as /heinneman/default.htm.The domain name and the file path are separated by a forwardslash (/). The file being retrieved in this example is default.htm.

Exercise 12.11 True or false?

a Broadband connection uses a higher bandwidth than a dial-upconnection.

b The Internet arrived when ARPANET adopted DNS standard.c The Web was the first graphical browser.d A URL contains a domain name.

2 What am I?a An organisation that provides access to the Internet for a fee.b The basis of the Internet.c Private network that uses a similar interface to the Web.d The address of a specific computer on the Internet.

3 Copy and complete the following by replacing the letter in bracketswith a suitable term:The Internet is a connected set of (a) using the TCP/IP standard. Adial-up connection requires a (b) and telephone line. The (c) wasintroduced in 1991 using the (d) protocol.

4 a What is provided by the Internet?b List three ways of establishing a connection to the Internet.c What contribution did the NSF make to the development of the

Internet?d Explain the difference between an intranet and an extranet.e Describe an IP address.f What is a URL?



Development5 Do research into the history of the Internet. Identify the key

historical events for the Internet. Include additional events notmentioned in this section. Construct a timeline of these events.Briefly describe and state the importance of each event.

6 Compare and contrast an intranet and the Internet. Outline thefeatures of the school intranet.

12. 2 Uses of the InternetThe Internet has many different uses such as email, research,chatting and messaging.

EmailEmail (electronic mail) is the transmission of electronic messagesusing a computer. Email is the most widely used Internet service.It requires email software to send, receive and manage email. Mostbrowsers include an email component and there are also separateemail applications such as Microsoft Outlook Express and NetscapeMail. In addition to email software the user needs an account andan email address.

Email addresses are unique and consist of two parts separated by the @ (‘at’) symbol in the form ‘name@domain name’. The firstpart is the name of the account. It is often a person’s username andis chosen where a user signs up for an account. The second part isthe domain name. It is the location of the person’s account on theInternet. The domain name identifies the specific computer orserver where the email messages are stored. For example, theaddress [email protected] consists of the following parts:• adam is the username• yahoo is the name of the account on the Internet• com is the organisational domain.An email message is usually short without a lot of details. Whenemail is sent, it is stored on the server where the recipient has anaccount. It stays on the server until the person checks their email.Email is sent using a header. The header contains informationneeded to deliver the message. The sender’s email address is usuallyautomatically inserted. The email header contains four main parts:• To—email address is the address of the person receiving the

message, which must be correctly typed



• Cc—carbon copy sendsthe same message toother people apart fromthe main recipient

• Bcc—blind carbon copysends a copy to otherpeople without revealingwho else got the message

• Subject—is the topic ofthe message or briefdescription—this is veryuseful for the receiver ofthe message.

After the email is read it can be deleted, printed or stored in anappropriate folder. The user can reply to an email message simplyby clicking on the ‘Reply’ or ‘Respond To’ command. A newmessage window is opened with the address of the original senderautomatically inserted. The previous message can be retained toremind the person of their original message. This is called quoting.The prefix ‘Re:’ may be added to the original subject line to identifythe ‘thread’ of the message. Forwarding messages involves sendingmessages you receive to someone else. An address book is used tostore email addresses. This saves time typing the address and avoidsthe problem of remembering each address. A mailing list is a groupof people who want to receive the same messages. A signature isseveral lines automatically added to the end of all email messages.It may include an email address, website, graphic, occupation andtelephone number.

An attachment is a file in its original condition and format thatis sent with the email message. It can be any kind of file, includingtext, graphic, video, audio or a program. Attachments are a usefulmeans of file transfer, as the receiver of the attachment will have anexact copy of the file. To send an attachment click the ‘Attach’ or‘Insert File’ command and select the file you want to send. Whensending an attachment it is important to include a briefexplanation in the main body of the email message. The file nameand the format of the attachment should be easily understood.

Netiquette is a code of acceptable behaviour users should followon the Internet. It covers rules for all aspects of the Internet such asthe email, chatting, newsgroups and discussion groups. If youfollow the rules of netiquette, you will be doing your part to make

Figure 12.3 Email message



life on the Internet easier for everybody. Some of the rules fornetiquette include:• keep messages short and to the point• be polite and avoid offensive language• avoid sending abusive or insulting messages (flames)—do not

participate in flame wars• avoid using all capital letters as it is considered shouting• use emoticons to express feelings such as :) for happy or :( for

sad• use abbreviations and acronyms such as ‘IRL’ for ‘in real life’ or

‘BTW’ for ‘by the way’• make the email subject line as meaningful as possible.

ResearchA search engine is a program that finds websites and web pages. Itaccesses a database of indexed websites that can be searched using akeyword. This index is built by regularly scanning for new websitesand accepting submissions from website authors. A search engine isaccessed using a browser. There are dozens of search enginesavailable on the Web, including Yahoo!, Alta Vista and Google (seeFigure 12.4). Each search engine has a different method of buildingits index and often obtains different results from the same search.Some search engines provide web directories. A web directoryorganises the Web into categories and then smaller subcategories.This allows the user to browse through the categories until theyfind a relevant site.

Search engines require the user to enter one or more keywordsrelated to their topic of interest. Most search engines allow users tosearch for specific items such as images. When the user enters akeyword and clicks the ‘Search’ button, the search engine scans its

index and lists thewebsites thatcontain thatkeyword. Somesearch enginesallow a search tobe restricted tojust Australia.This can be anadvantage whenresearching. Thelisting of websitesFigure 12.4 Yahoo! is one of many search engines on the Internet



is usually in order of relevance and is in the form of hyperlinks.This allows the user to access the listed web pages by simply clickingthem. Selecting a keyword is crucial to the success of a search. Toavoid being overloaded with information it is sensible to usekeywords that are very specific. Advance search options provideusers with more accurate results. The search can be restricted tofiles that were updated recently, particular file formats or websiteswithout certain words.

ChattingA chat provides a real time conversation with one person or withhundreds of people. People meet for a chat in a chat room (or chatchannel). A chat room is a virtual room usually on a particulartopic where people talk in groups or privately. To start a chat theuser connects to a chat server through a chat program. A chatprogram is included in your browser or can be downloaded fromthe Internet. Chat rooms supporting voice chats and video chats,where you can hear and see others, are becoming more popular.

Most chat rooms are open for everybody and users cancontribute to ongoing discussions by typing a few lines. Peoplemake friends and even have met future partners through chatsessions. However, people can make up different personalities andpretend to be anything they want to be. There are dangers for users,particularly children, from being exploited. Personal informationsuch as address, phone number or bank details should never begiven out in a chat session.

MessagingA newsgroup is an online area in which users conduct discussions ona particular topic. People read messages and join in discussions bysending or posting messages. The entire collection of newsgroups iscalled the Usenet (Users’ network). Newsgroups are read each dayby people from all over the world and provide a large diversity ofopinion and knowledge. Each newsgroup is classified into eightmajor categories: computers (comp.), social issues (soc.), science(sci.), recreation (rec.), discussion (talk.), miscellaneous (misc.),newsgroups (news.) and alternative (alt.).

A message board (or discussion group) is a popular web-baseddiscussion group (see Figure 12.5). Message boards are provided bymany websites. Discussion groups contain useful information. Forexample, FAQ (frequently asked questions) provide concise and

Archie wasdeveloped in 1989 at McGillUniversity inCanada. It was thefirst search engine.Administratorsfound out thathalf the trafficgoing into Canadawas accessingArchie on theircomputer. Theyclosed downArchie to outsideaccess.



detailed informationrelevant to that group.Some discussion groupsand newsgroups are onlyfor authorised membersand require a usernameand password. Forexample, a discussiongroup for a universitycourse would be restrictedto students taking thatcourse.

Instant messaging (IM) is a real-time Internet service thatnotifies users when one or more people are online. It has becomeone of the most popular Internet activities. Instant messagingservices are provided by many organisations such as ICQ, AOL,Microsoft and Yahoo!. They enable users to create buddy lists, checkwhether a buddy is online and exchange messages. There arecurrently no standards for instant messaging. Individuals on abuddy list need to be on the same or compatible instant messagingprogram.

Exercise 12.21 Explain the difference between:

a email and chattingb an attachment and a search enginec forwarding and replying.

2 Copy and complete the following sentences:a _______ are unique and consist of two parts separated by the @

symbol.b A mailing _______ is a group of people who want to receive the

same messages.c A web directory organises the Web into _______.d A _______ is a popular web-based discussion group.

3 What am I?a Used to store email addresses.b Code of acceptable behaviour users should follow on the

Internet.c Online area in which users conduct discussions on a particular

topic.d Real-time Internet service that notifies users when one or more

people are online.

Figure 12.5 Discussion group



4 a List the four parts of an email header.b Explain how a user replies to an email message.c Describe some of the rules for netiquette.d How does a search engine work?e What is a chat room?f What is provided by an instant messaging service?

Development5 Create or obtain two email addresses.

a Create a brief email message.b Send an email message to one of the email addresses.c Send a carbon copy and blind carbon copy to a friend.d Read and reply to the email message.e Create a simple mailing list.f Create and send an email message that contains an attachment.

6 Use three different search engines to find information aboutnetiquette. Compare and contrast the results of the three searchengines. Which search engine do you prefer? Give reasons for youranswer.

12. 3 Internet software and protocolsThere is a range of Internet software and types of protocols overthe Internet.

Browser softwareA web browser (or browser) is a software program that allows usersto access and view web pages. The most widely used web browsersare Internet Explorer and Netscape Navigator (see Figure 12.6).Online service providers (OSP) such as America Online (AOL) andCompuServe provide a browser free of charge as part of theirsubscription package. Web browsers display web pages, link toother web pages and download information to your computer.

Figure 12.6 Internet Explorer is one web browser



A web browser will display a website if the address (or location)is entered directly into the browser. Web pages that have video andanimation take longer to download, as they are larger in size.Browsers have the ability to store the addresses of frequently usedwebsites. These stored addresses are called favorites or bookmarks.Favorites save time accessing frequently used web pages. Thewebsites recently visited are called history. History can be displayedusing the browser. Web browsers also have a range of commands orbuttons that make them easier to use.

Table 12.1 Browser commands

Command or button Use

Back Displays the previous web page

Forward Displays the next web page

Stop Interrupts the download of a web page

Refresh Reloads the current web page from theserver

Home Returns to the home page

Search Displays web search tools

Favorites/Bookmark Addresses of frequently used websites

Web authoring softwareWeb authoring software is used to create and manage a multimediawebsite. Websites contain a range of data types such as animation,audio and streamed video. The web authoring software willposition and display objects, as they would be viewed through aweb browser. Many programs allow the user to manage entirewebsites using tools that automate repetitive tasks. Some popularweb authoring software includes:• Macromedia Dreamweaver—currently the industry standard

used by professional designers. It creates HTML code that islean and compatible with any browser or platform.

• Microsoft FrontPage—used by small business and home users.It has an intuitive layout with easy to use templates. Users havethe ability to view and edit the HTML code (see Figure 12.7).

Web authoring software allows the user to create a website structure.This may involve different levels and arranging groups of pages.Authoring software is designed to handle different data types. Text iscreated and formatted in many different ways such as using differentfonts. Text can be placed in ordered and unordered lists. Images areadded to a web page and edited as required. Users can also create

Tutorial


TCP/IP was originallydeveloped by theUnited StatesDepartment ofDefence forcomputers usingthe UNIXoperating system.It is now used byevery computer on the Internet.


and edit thumbnails. Audio, animations and video are easily insertedonto a web page. Authoring software also allows users to createtables, frames and forms. These are powerful tools used to createprofessional web pages.

Types of protocolsA protocol is a set of rules that governs the transmission of databetween computer devices. Some of the protocols used on theInternet include TCP/IP, HTTP, FTP and SMTP.

Transmission Control Protocol/Internet Protocol (TCP/IP) is acommon language for data transmission and error detection acrossthe Internet. It works by breaking information into smaller packetsof data. Each data packet contains the information and the addressof the receiving computer. The TCP standards inform the receivingcomputer what is inside the data packet and the IP standard tellsthe computer where and how to send the packet. Each data packetmight take a different route but eventually reaches the samedestination where all the packets are reassembled into the originalinformation.

Hypertext transfer protocol (HTTP) is a standard for transferringthe contents of a web page into a browser for viewing. It does notdownload files that make up the web page. HTTP is a one-waysystem as data is only transferred from the web server to thebrowser. Whenever ‘http’ appears in a URL the user is connecting toa web server and using the HTTP standard.

File transfer protocol (FTP) is a standard to upload anddownload files. An FTP server is a computer that allows users toupload and download files using FTP. Whenever ‘ftp’ appears in aURL the user isconnecting to a file serverand not a web server.Some form of file transferwill then take place.

Simple mail transferprotocol (SMTP) is astandard for outgoingemail. Most emailmessages are sent usingSMTP. POP3 (Post OfficeProtocol) is a standardfor incoming email. Figure 12.7 Popular web authoring software for the home user

includes Microsoft FrontPage



Project: My websitePreneeth Kumar is a student who wants to create a website about hisfamily, friends and interests. His sister Rani has agreed to supervise andassist in the development of the website. Preneeth solved the problemusing the four stages in project development.

• Define and analyse the problem: Preneeth ‘surfed’ the Internet and gathered design ideas from other personal websites. Heinvestigated the possibility of including pictures and videos of thefamily. A project plan was written.

• Design possible solutions: Preneeth developed two possiblesolutions. Each solution had a different website structure anddesign. Both solutions had a large multimedia component.Preneeth made a choice and presented his recommendation to his sister. Rani agreed but suggested a simplified version.

• Produce the solution: The website was constructed using MicrosoftFrontPage. He created the website structure and used a consistentlayout for each page. Preneeth imported pictures, audio and videointo the appropriate pages. Links were added and tested. His sisterprovided some technical advice on using tables and creatinganimation. Web pages and files were uploaded to a web server to become part of the Internet.

• Evaluate the solution: Preneeth tested his website using anothercomputer. He checked each web page and ensured all links wereworking. Preneeth was happy with his website.

Tasks1 Outline a website structure that would be appropriate for this

project.

2 Describe any social and ethical issues that would be a concern inthis project.

Exercise 12.31 Copy and complete the following sentences:

a Web _______ software is used to create and manage amultimedia website.

b The refresh command _______ the current web page from theserver.

c The _______ interrupts the download of a web page.d _______ is a standard for incoming mail.

2 True or false?a OSPs provide a browser as part of their subscription package.

ICT 12.1



b The ‘back’ command displays the next web page.c TCP/IP is a common language of data transmission and error

detection over the Internet.d FTP is a standard for outgoing email.

3 Copy and complete the following by replacing the letter in bracketswith a suitable term:A web (a) is a software program that allows users to access andview web (b). It will display a website if the (c) is entered directlyinto the browser. Web pages that have video take longer to (d).

4 a What is the advantage of ‘Favorites’ or ‘Bookmarks’?b Describe a website structure.c What is a protocol?d How does the TCP/IP work?e What protocol is used to upload and download files?f What is the hypertext transfer protocol?

Development5 Examine the range of software in your school to create a website.

Investigate any templates and wizards available with this software.Which piece of software do you prefer? Give reasons for your answer.

6 Create a web page that briefly describes the types of protocolsused on the Internet. Do research into Internet protocols to ensurethat the information on your web page is current.

12. 4 World Wide WebThe World Wide Web (www, also the Web) consists of a worldwidecollection of electronic documents that use the HTTP standard.The Web provides a user-friendly interface to the Internet.Resources on the Web are organised so that users can easily movefrom one resource to another. The connections to other computersare made automatically without being seen by the user. Theseconnections are made with the use of hypertext and a browser.A browser allows users to access and view websites.

A website is a group of electronic documents that presentinformation on a particular topic. Each electronic document iscalled a web page. A web page can contain text, images, sounds,video clips and links to other pages. Web pages are stored onpowerful computers called servers or web servers. Each server maystore thousands of web pages from different websites. To view aparticular web page your computer asks the server for a particularpage to be sent.

Lit 5.2



The Web is an information medium that covers a vast range oftopics on all aspects of society. It is used to access research,businesses, entertainment, software and personal interests. A keyfeature of the Web is interactivity. It allows the user to choose theirexperience on the Web. For example, you can access information,communicate using email, download software, listen to music,watch a video or play an interactive game. There are many types ofwebsites:• commercial—exist to sell their goods or services• information—present factual data• business—sites that provide support for an organisation such as

technical support• news—present information on the current events, sports,

money, life and weather (see Figure 12.8)• portal—provide Internet services such as search engines, email,

news, sports and reference material• personal—an individual’s web page and these sites contain

information on every topic.

Internet securityThe Internet has generated a whole underground industry ofthreats such as viruses, hackers and spam. However, there are manyways of controlling access to information on the Web.

A cookie is a file that is stored on the hard disk after the uservisits a website. It is used to measure a user’s behaviour and workflow habits. Privacy is often an issue raised with cookies. Cookiesstore the information about the web pages visited and the transactions

Figure 12.8 The ninemsn website contains different types of information



completed. However, most cookies are designed to improve yourexperience and allow organisations to target advertisements to yourtastes. Users do have the option of blocking all cookies or havingyour browser prompt you before accepting cookies.

A proxy server is a barrier to the Internet to ensure users aresecurely and productively accessing network resources. It letsadministrators limit access to objectionable content by filteringURLs. Administrators can control user access to specific documentsor websites. Proxy servers distribute and manage informationreducing network traffic and user wait times. Traffic time is reducedas the proxy server caches frequently accessed documents or entirewebsites. The proxy server only requests data from its source whenthat source has been updated or has expired.

Firewalls are used on the Internet or any network to check allincoming data for the purpose of verification and authentication. Itaims to protect a computer system from hackers trying to accesssensitive information. Firewalls are an important security measureon an intranet. All messages entering or leaving the intranet passthrough the firewall. It examines each message and blocks thosethat do not meet the specified security criteria. On large systemsmore than one firewall is necessary because barriers need to beplaced at all critical points.

Anti-virus software is used to scan a file or disk for a range ofknown viruses. A virus is a small program that attaches itself to anapplication. There is no guarantee that anti-virus software will stopevery virus, as new viruses are constantly appearing. However, ifusers download the latest virus definition files and regularly use theanti-virus program it will minimise the problem. Anti-virussoftware will also protect against email viruses, worms and Trojanhorses. An email virusattaches itself to an emailmessage. It spreads byautomatically mailingitself to each contact inthe user’s address book.Worms have the ability tocopy themselves frommachine to machine.Worms normally movearound and infect othermachines throughnetworks. Trojan horses

User

User

User

Proxy server

Firewall

Internet

Figure 12.9 Proxy server

Lit 5.3


The term ‘spam’comes from a‘Monty Python’sketch called the‘The Black Eagle’.The sketchcontained anannoying andrepetitive songabout spam.


are programs that claim to be one thing, such as a computer game,but will cause damage when the program is started.

Spam blocking software is protection against spam. Spam is thesending of a message through the Internet as a mass mailing to alarge number of recipients. The message is unwanted and oftencommercial. Fighting spam has been an ongoing battle. Anti-spammers develop a tool to block spam and spammers defeat thetool. For this reason spam blockers need to be regularly updated.There are different technologies used to block spam. The success ofspam blocking software is not only the quantity of spam it stopsbut also ensuring genuine email is received.

Anti-spyware software is protection against spyware. Spyware issoftware that installs on a computer in secret and transmits datafrom that computer. The data transmitted is usually personalinformation or information about computer usage. Users areinfected with spyware when they visit a website and are tricked intoinstalling it or they download a program with a spywarecomponent. The spyware component may be advertising softwareor adware. Anti-spyware software is a tool that removes spywareand prevents it from being installed.

Exercise 12.41 What am I?

a A worldwide collection of documents that use the HTTP standard.b A file that is stored on the hard disk after visits to a website.c Checks all incoming data for the purpose of verification and

authentication.d A program that claims to be one thing but will cause damage

when the program is started.2 Copy and complete the following by replacing the letter in brackets

with a suitable term:A (a) is a group of electronic documents that present (b) on aparticular topic. Each electronic document is called a web (c).Websites are stored on powerful computers called (d).

3 Unjumble these words:a ewb gepab oxpry rseevrc asntirviu aroswfte

4 a What is a key feature of the Web?b List six different types of websites.c What is the purpose of most cookies?d How does a proxy server improve security?



e How is a firewall used on an intranet?f What is spam?

Development5 Find at least one website where the focus is commercial,

information, business, news, portal and personal. What are thefeatures of these websites? Justify your classification of thesewebsites.

6 Why is the Web an important medium to publish information?Describe the ways the Web is different from other publishingmedia.

12. 5 Website developmentA website is made up of three types of web pages: home page,intermediate pages and content pages. Home page (index page) isthe first page viewed by a visitor. It provides information about thepurpose and subject matter of the website. A home page provides alink to other web pages. Many websites have intermediate pages. Anintermediate page is the next level down from the home page. Anintermediate page is accessible from the home page and links backto the home page. Intermediate pages provide structure and assistin the navigation of the website. They are a way of grouping thecontent pages. Content pages contain topic details and are usuallyaccessible from intermediate pages. Content pages usually contain alink back to the home page.

Hypertext markup language (HTML) is used to create webpages. HTML is a set of special instructions (called tags) thatindicate how parts of a document will be displayed. HTML codecan be created with any word processor or text editor, however, you

Lit 5.4



Tim Berners-Leedeveloped amethod of Internetaddressing calledURL, the languagefor encoding anddisplaying hyper-text documents called HTML and amethod of linkinghypertext docu-ments called HTTP.

do not need to write HTML code to create a web page. Manyprograms will automatically convert basic formatting features intoHTML codes. Web authoring software is used to create and managea website. You can layout text and graphics exactly the way youwant them to look and the software creates the HTML code.

Features of a websiteThe features of websites are changing to take advantage of newdevelopments in information technology. Some common featuresfound in websites include:• Contact information—traditional contact information is

needed on most websites such as address, phone, fax and email.It is appropriate to include as many different contact methodsas possible.

• Text—the look and style of text is an important factor in a webpage. The text content of a web page should display the essentialcontent.

• Graphic—pictures add interest and attraction to a web page.The most common formats for web images are JPEG and GIF.

• Thumbnail image—small preview representation of the ‘real’full size image. It downloads faster than the full size image. If avisitor wants to see the full size image they simply click on thethumbnail.

• Rollover—picture, icon or button that changes when the mouseis moved over it. A rollover is actually two images: one imagefor the ‘on’ condition and one image for the ‘off ’ condition. GIFfile format is often used for images as they must be displayedquickly.

• Animation—a flashing object quickly gets the visitor’sattention. It is used to direct the visitor to an area of the screenor an interesting feature.

• Streamed audio—used to provide background music or soundeffects. Streaming audio is heard before the entire file has beentransferred.

• Streamed video—video clips that play before the entire file hasbeen transferred. It is more dependent than streamed audio ona high bandwidth.

• Hyperlink—a link to another part of the same web page, aseparate web page, or location on the Internet. Hyperlinks aremade using text (hot word) or image (hot spot). Links areusually identified using an underlined character and/or adifferent text colour. Popular graphic links use buttons and



icons. Links areoften arranged inhorizontal rows orvertical columns toform a navigationtoolbar.

• Tables—rows andcolumns of cellsthat are filled withcharacters orgraphics. Tables areused to arrangeinformation in aprecise row andcolumn format. A variety of attributes can be applied to tablesand their cells, such as shading and borders.

• Lists—unordered lists do not have a numbered sequence. Entryin an unordered list is usually shown with a bullet. Ordered listsprovide a more structured look using a numbered sequence.

• Frames—space or boxes that hold an object. Each frame isconsidered a separate window and could be a separate HTMLdocument. Frames allow a banner, advertising message oranimation to be held in place while the visitor navigates thewebsite.

• Web forms—are tools to collect information, such as orders forgoods and services and results from surveys. Web forms have aninvisible part that processes the data and stores it in a database.Information is entered using text boxes, option buttons, checkboxes, list boxes, spin boxes.

Designing a websiteThere are three basic design principles for a website (see Figure 12.11):• Consistency—layout, format and style should be the same

throughout the website unless different data types demand achange. Readability is improved when similar items aregrouped.

• Navigation—people need to understand the structure of theweb pages. Colouring different areas of the page, using visualsymbols (icons and arrows), inserting clear page headers andcreating simple hyperlinks improves navigation.

• Simplicity—do not overuse design elements as this will createvisual clutter and confuse the visitor. The overuse of colour,

Figure 12.10 Features of a website (these materials have been reproducedwith the permission of eBay Inc. Copyright eBay Inc. All rights reserved)



sound and animations can be distracting. First impressions onthe Web are important. A visitor often forms an opinion of awebsite within the first minute of accessing the home page.

In addition to the above design principles there are design factorsfor these elements:• Text—clear and legible text using at most three different fonts.

Care should be taken using font styles such as bold and italic.Underlining is only used for hyperlinks. Long lines of text aredifficult to read.

• Colour—many different colours can be distracting and reducereadability. A colour scheme should not interfere with the mainmessage of the web page. Dark text on a light background orvice versa usually works well. Blue is often preferred for unusedlinks and purple for used links.

• Graphics—are used to create interest, however, they are slow todownload. When using graphics consider the size of the graphic,recognisable icons and whether the graphic fits easily on the screen.

• Animation—visitors seeking information from a website aredistracted by inappropriate animation. A small creative animationsuch as a comet-type effect can be effective.

• Audio and video—should not be an essential part of a web pageas some visitors might not have the right hardware or plug-in. Itis good practice to advise visitors about the size of audio andvideo files.

Figure 12.11 Website Tips

Lit 5.5



Exercise 12.51 Copy and complete the following sentences:

a A _______ image is a small preview representation of the ‘real’full size image.

b Links are usually identified using an _______ character and/or adifferent text colour.

c Each _______ is considered as a separate window and could be aseparate HTML document.

d Many different colours can be distracting and reduce _______.2 True or false?

a HTTP is used to create web pages.b Streaming audio is heard before the entire file has been

transferred.c Ordered lists are usually shown with a bullet.d Web forms have an invisible part that stores data in a database.

3 What am I?a The first page viewed by a visitor

to a website.b A set of special instructions that

indicate how parts of a document will be displayed.

c A picture, icon or button thatchanges when the mouse is movedover it.

d Rows and columns of cells that arefilled with characters or graphics.

4 a Describe an intermediate page of a website.

b How do you create HTML code?c Identify the contact information

that is needed on most websites.d What is a hyperlink?e Describe some of the information

often displayed in a frame.f Why is navigation an important

design element?

Development5 Investigate the features of three different

websites. Identify the features that you like andthose you dislike. Write a report that summarises yourinvestigation.

6 Create a simple website on a topic you find interesting.a Describe the features of the website.b Create and test the navigation used in your website. ICT 12.2



Part A: Multiple choice questionsSelect the alternative (a), (b), (c) or (d) that best answers each question.

1 Which of the following describes ahistorical event introduced in 1991using the HTTP standard?a ARPANETb World Wide Webc Emaild NSFnet

2 Which of the following is a privatenetwork that uses a similar interfaceto the Web?a Intranetb Extranetc ARPANETd BITNET

3 Which of the following is a programthat finds websites and web pages?a Find commandb Search programc Search engined Attachment

4 Which of the following describeschatting?a Online area in which users

conduct discussions on a particulartopic

b A popular web-based discussiongroup

c A real-time Internet service thatnotifies users when more than oneperson is online

d A real-time conversation with oneperson or with hundreds ofpeople

5 Which of the following is a standardto upload and download files?a SMTPb FTPc HTTPd TCP/IP

6 Which of the following is a commandor button that stores the addressesof frequently used websites?a Explorerb Savec Favorited List

7 What is a proxy server?a A barrier to the Internet to ensure

users are securely and productivelyaccessing network resources

b A file that is stored on the harddisk after the user visits a website

c A computer used to store web pagesd A computer used to store email

8 Which of the following statements isincorrect?a Cookies are an important security

measure for the intranetb Fighting spam has been an

ongoing battlec Anti-virus software is used to scan

a file or disk for a range of well-known viruses

d Worms have the ability to copythemselves from machine tomachine

9 Which of the following is a set ofspecial instructions used to createweb pages?a HTTPb Hypertextc HTMLd Web manager

10 Which of the following describes apicture, icon or button that changeswhen the mouse is moved over it?a Thumbnailb Rolloverc Hyperlinkd Graphic



Part B: Match the termFor each of the following statements (1 to 10), select from the list of terms (a to j)the one that most closely fits the statement.

Statements

1 A connected set of networks usingthe TCP/IP standard.

2 A private network that uses a similarinterface to the Web.

3 An online area in which users conductdiscussions on a particular topic.

4 Transmission of electronic messagesusing a computer.

5 A program that finds websites andweb pages.

6 A software program that allowsusers to access and view web pages.

7 A standard for transferring thecontents of a web page into abrowser for viewing.

8 A worldwide collection of electronicdocuments that use the HTTPstandard.

9 A file that is stored on the hard diskafter the user visits a website.

10 The first page of a website.

Termsa Cookieb Emailc Homed HTTPe Internet

f Intranetg Newsgrouph Search enginei Webj Web browser

Part C: Extended response questionsWrite at least one paragraph for each of the following:

1 Describe four major events in thehistory of the Internet. Which eventdo you consider the most important?Give a reason for your answer.

2 The Internet is having a significantimpact on our society. Outline fourways we are using the Internet.

3 Explain the difference between theseterms:a HTTP and FTPb web browser and web authoring

software.

4 What is the World Wide Web? Youranswer should explain interactivity,websites and web pages.

5 Spam is causing a problem for manypeople. Why is spam a problem?How can spam be reduced?

6 Tables, lists and frames are animportant feature of many websites.Distinguish between these tools.

e Tester



Project: Internet websiteCreate a website that presents information about the Internet. Suggested topicscould include history of the Internet, intranets, email, search engines, chatting,messaging, browsers, authoring software and some aspect of Internet security.This is a group project that requires each member to create at least one page inthe website. The design of the website and the navigation are importantcharacteristics for this project. Your solution should be developed using the fourstages in project development.

Project 5.1

Project 5.2

Project 5.3

Cross project 2

Cross project 3

Cross project 4


Documents

The Internet - web1.muirfield-h.schools.nsw.edu.auweb1.muirfield-h.schools.nsw.edu.au/technology/resources/IST/...An intranet is a private network that uses a similar interface to