Internet is a collection of local, regional and national computer networks that are linked together to exchange data and distribute processing tasks. The Internet evolved over the past thirty years from a fledging experiment with four computers into a vast information network that connects millions of microcomputers, minicomputers and mainframe computers. As of 1998, the Internet had more than 100 million users world wide, and that number is growing rapidly. The Internet is decentralized by design and, remarkably, this anarchy by design works well.
An ISP (Internet Service Provider) is a company that charges an ongoing fee for providing Internet access to businesses, organisations and individuals. The ISP provides the user with the necessary communications software (such as e-mail) and user account. The user supplies a modem that connects the computer to the user’s phone line. The user’s computer dials the ISP’s computer and establishes a connection over the phone line. Once connected the ISP routes data between the user’s computer and the Internet. Most ISPs offer dial-up Internet connections and electronic mail access, along with additional services. Some ISPs offer direct access to the Internet without the use of proprietary software.
World Wide Web is a computer network system that allows users to browse through information available
on computers round the world. The World Wide Web opened the Internet to millions of people interested in finding information. There are over one million Web sites around the world and the number is growing very quickly. The World Wide Web consists of documents called Web pages that contain information on a particular topic. A Web page might also contain one or more links that point to other Web pages. Links make it easy to follow a thread of related information, even if the pages are stored on computers located in different countries. Every Web page is stored as an HTML (HyperText Markup Language) document. An HTML document contains special instructions called HTML tags that tell a Web browser how to display the text, graphics, and background of a Web page. Uniform Resource Locator (URL) is the global address of documents and other resources on the World Wide Web. URLs can point to executable files that can be fetched using FTP (file transfer protocol, ftp://) or a Web page that can be retrieved using HTTP (hypertext transfer protocol, http://). To request a Web page the user either types in the URL address or uses a ‘mouse’ to click on a Web page link. After the http://, the next segment of the address is the server name. The server is the computer and software that make the data available. Most Web servers have domain names prefixed with WWW. By entering the Web server name, one accesses the site’s home page (The main page of a Website. Typically, the home page serves as an index or table of contents to other documents stored at the site). A home page is similar to the title page and table of contents in a book. It identifies the site and contains links to other pages at the site.
The Web browser is the gateway to commercial information services as well as the free sites on the Internet. A commercial information service provides access to computer-based information for a fee. In 1997, approximately 17 million people subscribed to the top four commercial information services: America On-Line, CompuServe, Microsoft Network and Prodigy.
The server sends the data for the Web page over the Internet to the computer. The data includes two things: the information the user wants to view and a set of instructions that tells the browser how to display it. The instructions include specifications for the colour of the background, the size of the text, and the placement of the graphics. Additional instructions tell the browser what to do when the user clicks on a link. The browser’s menu and tool bars help users navigate the Web as they follow the links. The Back and Forward buttons trace and retrace the users’ path through the links being followed from one Web page to another. The browser stores and can display a list of the pages being visited during each session. The browser can also store a list of favourite sites, often called bookmarks, to permit the user to jump directly to the site they wish to see instead of having to enter its URL every time.
on computers round the world. The World Wide Web opened the Internet to millions of people interested in finding information. There are over one million Web sites around the world and the number is growing very quickly. The World Wide Web consists of documents called Web pages that contain information on a particular topic. A Web page might also contain one or more links that point to other Web pages. Links make it easy to follow a thread of related information, even if the pages are stored on computers located in different countries. Every Web page is stored as an HTML (HyperText Markup Language) document. An HTML document contains special instructions called HTML tags that tell a Web browser how to display the text, graphics, and background of a Web page. Uniform Resource Locator (URL) is the global address of documents and other resources on the World Wide Web. URLs can point to executable files that can be fetched using FTP (file transfer protocol, ftp://) or a Web page that can be retrieved using HTTP (hypertext transfer protocol, http://). To request a Web page the user either types in the URL address or uses a ‘mouse’ to click on a Web page link. After the http://, the next segment of the address is the server name. The server is the computer and software that make the data available. Most Web servers have domain names prefixed with WWW. By entering the Web server name, one accesses the site’s home page (The main page of a Website. Typically, the home page serves as an index or table of contents to other documents stored at the site). A home page is similar to the title page and table of contents in a book. It identifies the site and contains links to other pages at the site.
The Web browser is the gateway to commercial information services as well as the free sites on the Internet. A commercial information service provides access to computer-based information for a fee. In 1997, approximately 17 million people subscribed to the top four commercial information services: America On-Line, CompuServe, Microsoft Network and Prodigy.
The server sends the data for the Web page over the Internet to the computer. The data includes two things: the information the user wants to view and a set of instructions that tells the browser how to display it. The instructions include specifications for the colour of the background, the size of the text, and the placement of the graphics. Additional instructions tell the browser what to do when the user clicks on a link. The browser’s menu and tool bars help users navigate the Web as they follow the links. The Back and Forward buttons trace and retrace the users’ path through the links being followed from one Web page to another. The browser stores and can display a list of the pages being visited during each session. The browser can also store a list of favourite sites, often called bookmarks, to permit the user to jump directly to the site they wish to see instead of having to enter its URL every time.
No comments:
Post a Comment