Internet Concept and Terminology The Internet The Internet

Internet Concept and Terminology

The Internet • The Internet is the largest computer system in the world. • The Internet is often called the Net, the Information Superhighway or Cyberspace. • The Internet consists of thousands of connected networks around the world. A network is a collection of computers that are connected to share information.

How do computers communicate ? protocols

TCP/IP Protocol • a set of rules governing how things are to be done TCP/IP (Transmission Control Protocol/ Internet Protocol) • a collective term of protocols used in Internet, governing. – the format of the messages transmitted – how the messages transmitted along the Internet

TCP/IP TCP • set rules on managing the correctness and the flow of the data IP • set rules of transmitting raw data along the Internet TCP/IP • set up rules for providing error-free channels for transmission

UNIX • It is a family of operating systems most widely used in the computer world • It is used by most of computers in the Internet • The UNIX commands can be used in the Internet

How to identify a host computer? DOMAIN/ HOST name physical address IP addressing

If only domain name is known, how do you know the IP address ? DNS

Domain Name System (DNS) • DNS servers on the Internet resolve Host/Domain names into IP addresses for locations on the Internet • It can do reverse lookup • Domain Name are registered and recognised throughout the Internet • Use on the Internet and on Intranet for all TCP/IP hosts – e. g. www. microsoft. com may be resolved to a 32 -bit binary address 207. 46. 130. 149

Hypertext • Hypertext is a linking that occurs within and between documents. • The basic mechanism is the capability to embed a hypertext link, a kind of jump point that allows a viewer to jump from a place in a Web page to any other Web page.

Hypertext Markup Language (HTML) • HTML is a computer language, which was developed to mark up, or encode hypertext document for display on the World Wide Web. • An HTML document is a plain ASCII (text) file with codes (called tags) inserted in the text to define elements in the document.

Web page /Web site address Web page. • It is a hypertext (HTML) document contained in a single file Web site address • the address that can identify the Web page

Homepage • It serves as an entry point to a Web site, and generally keep small, often serving simply as menus or directories to other Web pages that make up the rest of the Web site. • The idea is that a viewer need only display the homepage and then decide what else to view in the remainder of the Web site.

How do the Web pages transfer along the Internet ? protocol

Hyper. Text Transfer Protocol (HTTP) • HTTP is a plain text protocol that defines how the Web transports Web pages. • An understanding of detail mechanism is not necessary • It directly determines what you can and cannot send or receive through the Internet

Internet Service Provider (ISP) • A company or organization provides you access to the Internet • It may also give you space for a personal or non-commercial Web site at little or no cost

Internet address • Each page on the Internet has an address that identifies it. • This address is used to locate the page. Internet addresses are called URLs, which stand for Uniform Resource Locators. • A URL has several parts: – The first part of an Internet address is the protocol type

Internet address – Next is the address of the computer (server) on which the site is stored. – It also include a page name or address that identifies a specific page within a site. For example http: //www. microsoft. com/windows/abc. html

Uniform Resource Locator (URL) For example http: //www. microsoft. com/windows/abc. html Protocol computer address Path on Web server HTML file