Understanding How the Web Works

The Internet consists of tens of millions of computers throughout the world connected by cables. A few million of those computers are Web servers, computers that store, and dish out, copies of Web pages to anyone who asks for them. The program you use to access and view Web pages is called a Web browser. Many brands of Web browsers are on the market, including Firefox, Safari, Google Chrome, and Windows Internet Explorer. This tutorial covers Windows Internet Explorer Version 8, the Web browser that comes free with Windows 7.

Most Web sites use the HyperText Transfer Protocol (HTTP). For that reason, the URL (Uniform Resource Locator) for every Web page starts with http://. After the http:// comes the host name, which in the early days of the Internet typically indicated the name of the Web server to which you were connecting. Today, however, many Web servers host more than one Web site, and therefore the host name often identifies the Web application (web app) on the server that is serving up that particular site, rather than the server name itself.

Tip The Secure Sockets Layer (SSL) protocol is used by secure Web sites to encrypt traffic between the client (your computer) and the server. These secure sites use https:// rather than http:// at the beginning of the URL.

A Web site can consist of any number of pages. The first or main page for a Web site is often called its home page. In almost every case, you don't have to add the name of the site's home page in the URL, but instead just enter the protocol, host name, and domain name. For example, you can get to Microsoft's home page at http://www.microsoft.com. Google's home page is at http://www.google.com. eBay's home page is at http://www.ebay.com.

Tip The reason you usually don't have to include the home page name in the URL to get to the site home page is that the server sets a default name and serves up that page for all requests that don't specify any other page. Often, the home page is named default.htm, index.htm, or some variation of that, such as index.aspx.