Essay Networking: World Wide Web and Common Gateway Interface

Submitted By mohamadalawieh22
Words: 715
Pages: 3

May/7/2014
Week 2 Research 3

Common gateway interface (CGI): The common gateway interface (CGI) is a standard way for a Web server to pass a Web user's request to an application program and to receive data back to forward to the user. When the user requests a Web page (for example, by clicking on a highlighted word or entering a Web site address), the server sends back the requested page. However, when a user fills out a form on a Web page and sends it in, it usually needs to be processed by an application program. The Web server typically passes the form information to a small application program that processes the data and may send back a confirmation message. This method or convention for passing data back and forth between the server and the application is called the common gateway interface (CGI). It is part of the Web's Hypertext Transfer Protocol (HTTP).
ISAPI: (Internet Server Application Program Interface) is a set of Windows program calls that let you write a Web server application that will run faster than a common gateway interface (CGI) application. A disadvantage of a CGI application (or "executable file," as it is sometimes called) is that each time it is run, it runs as a separate process with its own address space, resulting in extra instructions that have to be performed, especially if many instances of it are running on behalf of users. Using ISAPI, you create a dynamic link library (DLL) application file that can run as part of the Hypertext Transport Protocol (HTTP) application's process and address space. The DLL files are loaded into the computer when HTTP is started and remain there as long as they are needed; they don't have to be located and read into storage as frequently as a CGI application.
Server Side Includes (SSI): is a simple interpreted server-side scripting language used almost exclusively for the Web.
The most frequent use of SSI is to include the contents of one or more files into a web page on a web server. For example, a web page containing a daily quotation could include the quotation by placing the following code into the file of the web page:

With one change of the quote.txt file, all pages including the file will display the latest daily quotation. The inclusion is not limited to files, and may also be the text output from a program, or the value of a system variable such as the current time.
Server Side Includes is useful for including a common piece of code throughout a site, such as a page header, page footer and a navigation menu. Conditional navigation menus can be conditionally included using control directives.

An Active Server Page (ASP): is an HTML page that includes one or more scripts (small embedded programs) that are processed on a Microsoft Web server before the page is sent to the user. An ASP is somewhat similar to a