CGI (Common Gateway Interface)

An acronym for Common Gateway Interface, CGI is an interface program that enables an Internet server to run external programs to perform a specific function. Also referred to as gateways or CGI "scripts," these programs generally consist of a set of instructions written in a programming language like C or PERL that process requests from a browser, execute a program and format the results in HTML so they can be displayed in the browser. Gateway scripts are commonly used to add interactivity to a web page by allowing users to do things like fill out and submit forms for processing (as in an order form for an online catalog); query databases by submitting search requests; and register or gain access to password-protected areas of a site. CGI scripts are also used to implement a variety of tracking and measurement systems on a website..