Short for Common Gateway Interface script. An external application thatis executed by an HTTP server in response to a request by a client, such as a Web browser. Generally, the CGI script is invoked when the user clicks on an element on a Web page, such as a link or an image. Communicationbetween the script and the server is carried out via the CGI specification. Although CGI scripts can be written inmany programming languages, the most frequently used language is Perl, a small but robust language that iscommon on the UNIX platform. CGI scripts are used to provide interactivity on a Web page, including suchfeatures as forms that users can fill out, image maps that contain links to other Web pages or resources, and linksthat users can click on to send e-mail to a specified address.