Common Gateway Interface (CGI) is a standard way for web servers to interface with executable programs installed on a server that generate web pages dynamically. Such programs are known as CGI scripts or simply CGIs; they are usually written in a scripting language, but can be written in any programming language.
CGI is a method used to exchange data between the server and the web browser. CGI is a set of standards where a program or script can send data back to the web server where it can be processed. CGI is not used widely today. But it was very popular when internet was immerged. CGI is very easy to learn so there are no pre –requisite required.
In this course we have covered introduction to CGI, what CGI provides, mechanism of CGI, getting user input, CGI features, apache for CGI, work of CGI, forms and CGI, pros and cons of CGI, applications and final.
So this was essential coverage, CGI is outdated technology today. But still if you want to learn more about CGI then you can go to http://www.fastcgi.com/devkit/doc/fastcgi-prog-guide/ch1intro.htm