A script is a program or sequence of instructions that is interpreted or carried out by another program rather than by the computer processor. CGI (Common Gateway Interface) is a standard for interfacing external applications with information servers, such as HTTP or Web servers. A plain HTML document is static, which means it exists in a constant state: a text file that doesn’t change. A CGI program, on the other hand, is executed in real-time, so that it can output dynamic information. Common CGI features are “hit” counters, redirection and on-the-fly generation of Web pages, database queries, guest books or feed back forms. CGI is a consistent way for data to be passed from the user’s request to the application program and back to the user.