THD204 - THD204 TMA03 - Part 1 World Wide Web Overview
The Internet
The Internet, more commonly called "The Net" is a world-wide network of computer networks, a network of networks in which users of any computer can get information from any other connected computer providing they have the necessary permissions. The Internet was originally created to allow research computers at different universities to talk to each other, this was developed by ARPA (Advanced Research Projects Agency) in 1969. ARPA was a United States military funded agency and the requirement was for remote military command and control computers to talk to each other.
The Internet now a public network accessible by hundreds of millions of people worldwide who have Internet access. User access is achieved through the use of existing public telecommunication networks. The Internet uses a set of protocols known as TCP/IP (Transmission Control Protocol/Internet Protocol). Each network connected to the Internet is referred to as a Site. The most widely used application on the Net is e-mail, people can 'live' chat using IRC (Internet Relay Chat) and recent developments in internet telephony allow for real-time voice and video conversations.
The World Wide Web
The World Wide Web also known as "The Web" is a service that runs on "The Net" and allows access the information available on sites throughout "The Net". The WWW is the most widely used part of the "Net". The Web is a wide area hypermedia information retrieval initiative aiming to give universal access to a large universe of documents.
Web Sites and Pages
The Web consist of pages called Web Pages that contain information on a particular topic, a Web Page may also contain links to one or more other Web Pages. Links are pointers to other Web pages that make it easier to follow a thread of related information even if the pages are stored on different computers in different countries. To offer Web pages the Internet Site must set up with Web server software and format its pages using a Hypertext Markup Language (HTML) editor. The HTML editor creates the links between pages, displays links on boldfaced underlined text, and positions graphics.
Each Web page has a unique address called a Uniform Resource Locator (URL). To access a Web Page you must either follow a link or type a URL. You can find Web addresses in magazines or online through a directory of Web pages at a Search Engine such as Yahoo - www.yahoo.com.
Accessing pages
To access all this information you need a computer with Internet access and software known as a Web Browser. The Web Browser displays text, graphics, and links to other pages. Popular web browser packages are Internet Explorer, Netscape and Opera plus many more.
Common Protocols
HTTP - HyperText Transfer Protocol, is the set of rules for exchanging files on the World Wide Web. HTTP is an application protocol.
FTP - File Transfer Protocol, a standard Internet protocol, is the simplest way to exchange files between computers on the Internet.
HTML - HyperText Markup Language, is the set of markup symbols or codes inserted in a file intended for display on a World Wide Web browser page. The markup tells the Web browser how to display a Web page's words and images for the user.
TCP/IP - Transfer Control Protocol / Internet Protocol is the basic communication protocol of the Internet.
SMTP - Simple Mail Transfer Protocol, is a TCP/IP protocol used in sending and receiving e-mail. However, since it's limited in its ability to queue messages at the receiving end, it's usually used with one of two other protocols, POP3 or IMAP.
POP3 - Post Office Protocol, is the most recent version of a standard protocol for receiving e-mail. POP3 is a client/server protocol in which e-mail is received and held for you by your Internet server.
IMAP - Internet Message Access Protocol, a standard protocol for accessing e-mail from your local server. This is a client/server protocol in which e-mail is received and held for you by your Internet server.
MIME - Multi-Purpose Internet Mail Extensions, an extension of the original Internet e-mail protocol that allows people to exchange different kinds of data files on the Internet: audio, video, images, application programs etc., as well as the ASCII handled in the original protocol, SMTP.
Uses
Uses of the WWW include information searches, e-commerce - online banking, shopping, share trading etc., e-mail, file transfers, chatting, newsgroups, online gaming, to name but a few.