Exploring the Internet

91.113-031Instructor: Patrick Krolak

Topic: What is the Internet • Internet Growth• How does the Internet works• Basic Concepts

P. D. Krolak & M. S. Krolak ©2005

The Internet

Some basic information about the Internet, about how it works, and how it is creating changes in our private life, society, business and government.

Source:

What is the Internet?

“The Federal Networking Council (FNC) agrees that the following language reflects our definition of the term "Internet".

"Internet" refers to the global information system that --

(i) is logically linked together by a globally unique address space based on the Internet Protocol (IP) or its subsequent extensions/follow-ons;

(ii) is able to support communications using the Transmission Control Protocol/Internet Protocol (TCP/IP) suite or its subsequent extensions/follow-ons, and/or other IP-compatible protocols; and

(iii) provides, uses or makes accessible, either publicly or privately, high level services layered on the communications and related infrastructure described herein."

The Internet Usage World Wide

WORLD INTERNET USAGE AND POPULATION STATISTICS

World Regions Population ( 2005 Est.)

Population % of World

Internet Usage, Latest Data

Usage Growth

2000-2005

% Population ( Penetration )

World Users %

Africa 896,721,874 14.0 % 16,174,600 258.3 % 1.8 % 1.7 % Asia 3,622,994,130 56.4 % 323,756,956 183.2 % 8.9 % 34.5 % Europe 731,018,523 11.4 % 269,036,096 161.0 % 36.8 % 28.7 % Middle East 260,814,179 4.1 % 21,770,700 311.9 % 8.3 % 2.3 % North America 328,387,059 5.1 % 223,392,807 106.7 % 68.0 % 23.8 % Latin America/Caribbean 546,723,509 8.5 % 68,130,804 277.1 % 12.5 % 7.3 %

Oceania / Australia 33,443,448 0.5 % 16,448,966 115.9 % 49.2 % 1.8 % WORLD TOTAL 6,420,102,722 100.0 % 938,710,929 160.0 % 14.6 % 100.0 % NOTES: (1) Internet Usage and World Population Statistics were updated on July 23, 2005. (2) For regional information, click on each world region. (3) Demographic (Population) numbers are based on data contained in the world-gazetteer website. (4) Internet usage information comes from data published by Nielsen//NetRatings, by the International Telecommunications Union, by local NICs, and by other other reliable sources. (5) For definitions, disclaimer, and navigation help, see the Site Surfing Guide. (6) Information from this site may be cited, giving due credit and establishing an active link back to www.internetworldstats.com. ©Copyright 2005, Miniwatts International, LLC. All rights reserved.

Source: http://www.internetworldstats.com/stats.htm

The Internet growth

Source: http://www.wilsonweb.com/wmt6/ad-anorexia.htm

Growth in Internet Domains (Websites)

Source: http://www.isc.org/index.pl?/ops/ds/

How does the Internet Work?

Some basic ideas to help understand the technology and the jargon.

Source:

What is a protocol?

Source: http://www.webopedia.com/TERM/p/protocol.html

Protocol:

An agreed-upon format for transmitting data between two devices. The protocol determines the following: – the type of error checking to be used – data compression method, if any – how the sending device will indicate that it has

finished sending a message – how the receiving device will indicate that it has

received a message

The Internet

• Internet is a massive connection of computers. The Internet is not a single network but an inter connected collection of thousands of computer networks. The networks use a standard computer protocols called TCP/IP.

• Ever computer has a four number address called an IP address eg. [22.56.34.99]. Each of the 4 numbers has a value between 0 and 255. The numbers are separated by a “.”

• Each computer has a domain name that is easier for people to remember, eg. www.uml.edu

Client – Server model

• One computer – normally the one you are on asks the question. It is called the client

• The other – answers the question, provides information, data, or pages that it sends back to the client. This computer is called the server.

• The client normally uses a program called the browser to display the data and send the question to the server.

Transmission Control Protocol/Internet Protocol (TCP/IP)

Source:

TCP/IP is the means by which the Internet transmits information from one computer to the other.

IP is a series of protocols for creating information packets called datagrams. Think of a packet like a letter. Each packet has a wrapper with a destination address and data inside.

TCP – Establishes a connection between the receiver and the

sender. – Insures that stream of packets arrive in order that they

were sent and – guarantees delivery.

The World Wide Web

Source: http://www.learnthenet.com/english/html/13wworks.htm

The Web has the following elements:

1. A web browser for displaying text, images, & media

2. Your (the client) computer connected to the Internet through an Internet Service Provider (ISP).

3. The Internet (a communications network) using a protocol (TCP/IP) and routers to direct the messages to computers (servers)

Client server computing

Source:http://www.learnthenet.com/english/html/13wworks.htm

The web uses a client/server model:• The client asks for a service • The service is provided by the server.• The request and the answer are broken into packets

of information and sent over the Internet.

The Web Browser

Source: http://www.webopedia.com/TERM/b/browser.html

The Browser:

Short for Web browser, a software application used to locate and display Web pages. The two most popular browsers are Netscape Navigator and Microsoft Internet Explorer. Both of these are graphical browsers, which means that they can display graphics as well as text. In addition, most modern browsers can present multimedia information, including sound and video, though they require plug-ins for some formats

Hypertext

A special type of database system, invented by Ted Nelson in the 1960s, in which objects (text, pictures, music, programs, and so on) can be creatively linked to each other. When you select an object, you can see all the other objects that are linked to it. You can move from one object to another even though they might have very different forms. For example, while reading a document about Mozart,

– you might click on the phrase Violin Concerto in A Major, which could display the written score or perhaps even invoke a recording of the concerto.

– Clicking on the name Mozart might cause various illustrations of Mozart to appear on the screen.

– The icons that you select to view associated objects are called Hypertext links or buttons.

Source: http://www.webopedia.com/TERM/h/hypertext.html

The Universal Resource Locator (URL)

The URL is divided into three parts:1. The Protocol2. The Domain Name or IP address3. The pathThus a URL defines a service (protocol) to be preformed,

the location on the Internet of the Server and the path to the file on Server associated with the service.

Source:

The URL Protocol

• The URL protocol tells the server what function is being requested and what protocol to use to read the message.

• The protocol ends with “://” -- the domain name or IP address follows.

• Common protocols:– http (Hyper text transfer)– ftp (file transfer)

Source:

The Domain Name

• The Internet is able to locate documents because every computer connected to the Internet has an address, the IP address made up of a 4-tuple.

• The IP address is not easy for humans to remember so there is a domain name that is associated with each computer or web site.

• The domain name is translated into an IP address by a Domain Name Server (DNS).

• The domain name is made up of the computer name and the upper level domain. The name is a series of names separated by “.” (read dot), e.g. ceweb.uml.edu

Source:

The Path

The path describes where to find the information in the computer:

1. The path starts with a “/” (called a slash) which presents the root of the path. The default is the computer’s website.

2. Each subdirectory is then follows again separated by “/” until the file is reached.

3. The file has a file name including an extension, e.g. index.html

Source:

Hypertext and HTML

• The Hyper Text Markup Language (HTML) is a standard for creating hypertext documents.

• The browser client requests the html document (also called hyper text media) from the web server and then uses the markup (tags) in the document to display the document. The tags tell the browser what the author’s intention was for how to best display the document, e.g. should the text be bolded, italic, underline, etc. The browser then does its best to display the document within the computer’s limitations.

The Internet as Change Agent

Surfing the Web

• Surfing the web (browsing) – using a browser to search and read html documents and other media (mp3s and videos).

• Using the hyperlinks in these documents to go to other documents on the web.

• The getting information off the web is nonlinear as opposed to linearly reading a book (serially one page follows the other). Thus the web is more like a buffet than a dinner. We follow our interests from one page to another.

Internet communications

• The web and other Internet innovations have opened the door to a world of communication and learning that can be compared to that of the discovery of the printing press.

• Email, newsgroups, chat, and instant messaging (IM) are widely used and children 8-12 and teenagers are the using these tools on a daily basis.

• Blogs that record thoughts and newsgroups are widely used by men 30-50.

• The elderly are now fastest growing group of new users for online dating and socialization.

Typical Usage patterns

What is a blog?

def. blog

n.

1. an online diary; a personal chronological log of thoughts published on a Web page; also called Weblog, Web log

Source: Webster's New Millennium™ Dictionary of English, Preview Edition (v 0.9.6) Copyright © 2003-2005 Lexico Publishing Group, LLC

Growth in Blogs (Websites)

The blogosphere may be a baby, but it is booming, Web trackers say.

Although the concept of "blogging" didn't exist a decade ago, today the number of blogs doubles every five months. And a new blog is created almost every second — that's more than 80,000 every day, according to the blog tracking group Technorati.

"The tools to create blogs have become markedly easier and more accessible," Technorati Founder and CEO David L. Sifry told CBSNews.com. "If the numbers continue going the way that they are, you should expect to see close to 30 million blogs by March of

next year and should be seeing 2 million posts a day."

Source:http://www.cbsnews.com/stories/2005/08/02/tech/main713494.shtml

The Internet and Society

• The Internet is creating a virtual world of personal relationships. People met and socialize on the ‘net’.

• They can assume whatever personality they desire, e.g. male/female, young/old.

• The Internet is shrinking the world -- people from all over the world can communicate in chat rooms, Blogs, email, and even video conferences.

The Internet is changing government and business

• The Internet is a key technology in globalization.

• Blogs and online news is changing the way people get their news.

• Online shopping is creating new channels for marketing and sales.

• Supply chains are shorter and more efficient.

• Governments are modifying the way it delivers goods and services, advertises and purchases resources, and collects revenues.