WHAT IS INTERNET

The internet, sometimes simply called “the Net” is a worldwide system of computer networks- a network of networks in which users at any one computer can, if they have permission, get information from any other computer (and sometimes talk directly to users  at other computer). It was conceived by the Advanced Research Projects Agency (ARPA) of the U.S Government in 1969 and was first known an ARPANET.  The original aim was to create a  network  that would allow users of a research computer at one university to be able to talk to” research computer at other Universities. A side benefit of ARPANET’s design was that, because massage could be routed or rerouted in more than one direction, the network could continue to function even if parts of it were destroyed in the event of a military attack or other disaster.  Today, the internet is a public, cooperative, and self-sustaining facility accessible to hundreds of millions of people worlwide. Physically, the internet uses a portion of total resources of the currently existing public telecommunication networks. Technically, what distinguishes the internet its use of a set of protocols called TCP/IP (Transmission Control Protocol/Internet Protocol). Two recent adaptations of internet technology, the inranet and the extranet, also make use of the TCP/IP protocol. For many internet users, eletronic mail  has pratically replaced the postal service for short written transactions. Electronic mail is the most widely used application on the Net. You can also carry out live conversations with other computer users, using Internet Relay Chat (IRC). More recently, internet telephony hardware and software allow real-time voice conversations. The most widely use of internet is Worl Wide Web (www). Its outstanding feature is hypertext, a method of nistant cross-referencing. In most we site, cetain word or phrases appear in text of a different color than the rest; oftten this text is also underlined. When you select one of these words or phrases, you will be transferred to the site or page that is relevant to this word or phrases.  Sometimes there are buttons, images, or portions of image that are  “clickable.” If you move the pointer over a spot on a web site and the pointer changes into a hand, this indicates that you can click and be transferred to another site. Using the web, you have access to millioms of pages of information. Web browsing is done with web browser, the most popular of wich are Microsoft Internet Explore and Netscape Navigator. The appearance of a particular web site may vary slightly depending on the browser you use. Also later versions of a particular browser are able to render more bells and whistles such as animation, virtual reality, sound, and music files, than earlier version.