Web server extension
a program written in native code i.e. an executable or a script that is interpreted by an interpreter running on the web server, that extends the functionality of the web server and allows it to generate content at the time of the HTTP request
Common Gateway Interface
a gateway between a web server and a web server extension that tells the server how to send information to a web server extension and what the server should do after receiving information from a web server extension
Dynamic web page content
content that is generated when the web browser request is received