chapter  3
26 Pages

HTML, JavaScript, and Web Pages

The Internet is a network of networks. It is a linkage of smaller networks each of which agrees to use the same communication rules (called a protocol) for exchanging information. The Internet protocol is a transmission control protocol/Internet protocol (TCP/IP). The Internet is a great place to acquire information from across the world. The user can also acquire computer software or even work on other computers located thousands of miles away. Major Internet Operations are summarized as follows:

Internet Operations Purposes

E-mail Exchange electronic messages FTP (File Transfer Protocol) Retrieve fi les from a computer elsewhere on the Internet Telnet Work on a computer elsewhere on the Internet

(e.g., log on the UMD mainframe from your home) World Wide Web Transfer text, images, and sound on the Internet

To access the Internet, the computer must be linked to the Internet through an Internet provider (usually a local telephone company). Computers on the Internet play two types of roles: server and client. On the Internet, a server is a computer that manages its data including text, images, video clips, and sound. A server computer is set up by an individual or organization and it allows other computers to access its data. On the Web, a server is also called a Web site. A client is a PC that can access data on a server. On the Web, the software supporting the client operations is called a browser. Netscape Navigator and Microsoft Internet Explorer are the two most popular Web browsers. A browser uses a graphical user interface (GUI) which is supported by a local operating system, for example, Microsoft Windows.