Introduction to Web Servers
In a Nutshell - CIW Course Section 3, Part A1, Chapter 6
URL Request Processing
The protocol used for making a Web request is the Hypertext Transfer Protocol (HTTP), or the enhanced version Hypertext Transfer Protocol Secure (HTTPS). The client browser sends a request for a page, which is in reality just a file. The server processes this request and returns the file to the client.
The URL is comprised of several distinct components. The protocol to be used, the server or site name, optionally the port number, and the file or page. There may also be parameters passed to the file or page.
If the server is using port 80, the default, then it does not need to be specified in the URL. I have shown the parameter as optional, which is not strictly true, if a page expects to be passed a value then it will be required. Most browsers will use the HTTP protocol even if it is not stated in the URL.
The site name will be the domain name of the site, or on an intranet may just be the server name on the network. It may also be the IP address of the server.
The target file may be in a directory, be this a physical directory or a virtual directory. In this the file name must included the relative path to the file.
Common Web Servers
What's the first name that comes to mind when you think about Web server software? I would wager it will be Apache or IIS. I think Apache, because it is open source, is the server that runs more Web sites than any other. Internet Information Server (IIS) being a Microsoft Product is not far behind it, with many hosting providers offering a choice of both.
iPlanet and Zeus server are both major contenders with Zeus powering, amongst others, the eBay sites.