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Unit C and Buyer’s Guide
Pages C1 to C32
and
Pages 1 to 16
Internet History
Cyberspace – who coined the term?Internetwork or internet is a collection of two or more networksGrowth of Internet
1969 – ARPANET links four networks1985 – NSF expands ARPANET/education1986 – 2,000 host computers – Web, FTP, Usenet, IRC1990s – User-friendly software, 100 terabytes per week19 Degrees of Kevin Bacon?
Internet TerminologyNSPs (Network Service Providers) connect at NAPs (Network Access Points)Internet Backbone – a major set of communication links or routesISP – Internet Service ProviderConnection speed vs. transfer rateConnection types
Dial-up – POTS and modemCable Modem and DSL (Digital Subscriber Line)T1, T3, satellite, microwave, PDA, cell phone, etc.
Communications Software Protocols
A protocol is a set of rulesTCP/IP – primary protocol for Internet
• IP address = four dotted numbers between 0 and 255 May be static (semi-permanent) or dynamic (temporary)
• Routers forward information to/from IP addresses
SLIP and PPP – used for dial-up
PPTP and VPN (not in book)
CHAP (not in book)
HTTP is the protocol used to transmit Web pages
Hosts, Domains, and URLsMnemonic name = FQDN (domain name)
Ends in three-letter extension (.com, .gov, .edu)Extension indicates the top level domainCountries, states, and other organizations may have standard extensionsMaintained by InterNIC
A site is a virtual locationURL is the “address” of a document or site
index and .htm or .html defaultwww and http default with exceptions
The Six U
The World Wide Web is an Internet service that stores and provides information – but does it exist?Hypertext links – (usually) underlined text in a document which leads to another document or another portion of the same documentWeb portals and search engines
Web BrowsersA Web Browser is a multi-purpose program that allows the user to view Web pages on different types of servers
Microsoft Internet Explorer and Netscape NavigatorLynx (text) and Opera
Access Web pages by typing an IP address or a URL, or by linking from another pageCommon graphical features404, Bad Gateway, timeout and other errors
Scavenger Hunt, Anyone?Search engines are Web sites that search other Web pages for keywords or topics
Generic topic search engines (google.com, yahoo.com, msn.com, altavista.com, etc.)Bots or pricing services
• pricefarmer.com• bestbookbuys.com
2.2 liter 4-cylinder vs. 3.8 liter V8Dictionaries/encyclopedias can be search engines
Merriam Webster Onlinepcwebopedia.com and whatis.com
Electronic Mail
An e-mail message or letter is a document, created by a user with e-mail client software, (usually) sent to (at least) another user through (at least one) e-mail serverStore-and-forward = server stores messageGateways send mail across systemsE-mail address = [email protected] or low-cost e-mail at hotmail.com, yahoo.com, angelfire.com, lycos.com, juno.com, many other sites and ISPsCc: vs Bcc:, mailing lists, return receipt, priority
Internet, World Wide Web, internet, intranet, extranet (huh?)
An internet (with a lowercase “i”) is composed of two or more connecting networks.The Internet (with a capital “I”) is a collection of local, regional, national, and international computer networks that are linked together to exchange data and distribute processing tasks.The World Wide Web is an Internet service in a hypertext environment. An intranet is a mini-internet designed primarily for use by employees exchanging data and information within an organization. An intranet ensures privacy by residing behind a firewall. An extranet is basically an intranet that provides various levels of accessibility to “outsiders” who have been assigned a username and password.
Multimedia on the WebStreaming media plays one segment of a file while receiving later segmentsIn-place multimedia (animated .gif) vs. overlayPlug-in – additional software that increases browser features and abilities (needed for Flash, RealPlayer, QuickTime)Push vs. Pull
Pull – information directly requested by the user at the current timePush – not directly requested by user right now
• May include desired but automated content (newsletter, webcast, stock quotes)
• May be intensely annoying (ads, INTERSTITIALS)
How to Start and Use Browsers on Campus
Demo only – no organized notes
Downloading and Uploading
Downloading means obtaining a file (usually FROM a server or remote site)
Uploading means to send a file (usually TO a server or remote site)
Can upload and download with FTP (WS-FTP)
Self-extracting files and zipped files
How to save a web page or element
Interacting online
Discussion groups – asynchronous, savedBulletin or message boards, WebCT
Chat group – synchronous, not saved
Safety measures
CCSN rules
Multiplayer gaming (e.g., MSN Zone)
HTM What the L?!?
HTML = Hyper Text Markup LanguageTags are instructions on how to display a page
Title and body - demo
Some tags require pairs – demo
Dynamic HTML, XML (.NET), Java, ActiveX
Ways to create HTML documentsBasic text editor – Notepad
Web authoring software – FrontPage, HomePage, Word
Publishing a Web Site
Design pointsPlanned links, templates, consistency
Colors for text and background
Copyrights, disclaimers, etc.
Identification, title, dates
Keep it up-to-date
Web host (may be an ISP)
Connecting to the Internet
Home connectionComputer, modem, telephone or other line
• Note that the book does not consider cable or DSL!
ISP
Necessary dial-up or other software• May include device drivers
• Requires a username and password to access ISP
Business and school connections usually do NOT use 56K modems and standard telephone lines!
Internet Scams, Hoaxes, and Misinformation
The Internet is now the fastest way to disseminate misinformation (people who won’t believe something in the traditional media -- which may have a wider audience -- will accept, spread, and perpetuate rumors from the Internet or e-mail, while being skeptical of TV or printed news; traditional media may also spread stories first reported on the Web)
Chain letters are (usually authorless) e-mails that request you to pass them onViruses (malicious, self-replicating programs) can be spread by the e-mail and downloaded filesRumors and semi-truthsQuestionable products and services
Buyer’s Guide pp 2-4
Bays provide areas in the computer case for installing devices
Internal – no opening to the outside (bracket)External – device is accessible outside the case
Port or expansion slot for printer or cardsHard Drives – EIDE, UltraATA, SCSI, DMACD-ROM speeds – advertised vs. average
Book math?
Buyer’s Guide pp 4, 6, 7
Cache is high-speed memory that gives the CPU more-rapid access to data
Level 1 (L1) – built into processor
Level 2 (L2) – separate chip, still faster than RAM
Benchmark – performance test for computersPassive vs. active matrix displays on notebooksPort replicators, PCMCIA, docking stationsHot-swapping for batteries and devices
Buyer’s Guide pp 8-14
Various mice (scrolling, trackball, IR)Keyboards (104, ergonomic, Braille)Printer types and considerations
Duty cycle = # of pages per monthReview cpi, dpi, ppm, CMYK
Sound cards, .wav, midi, MP3Modems, faxmodems, scannersReview backup typesReview user support optionsReview buying specifications
Buyer’s Guide pp 15-16Computer-use jobs have a majority of tasks that do not involve a computer (e.g., mechanic, clerk)Computer-related jobs utilize the unique abilities of computers in non-computer industries (e.g., graphic artist, architect)Computer-specific jobs would not exist without computers
Education usually involves a college degreeIndustry certification may be helpfulWork conditions and salaryOnline recruiting, résumés, research