CGI-BIN

CGI stands for Common Gateway Interface. In the beginning, CGI was used as an interface between scripts executed on the web server and user interaction. Modules were not directly built into the web server, and thus had to be executed somehow. This execution was done where executable programs were placed in a CGI-BIN directory, designating them separate from static pages.

It is a common misconception that **perl** files (ending in .pl or .cgi) are CGI itself. CGI-BIN is just an interface - it is possible to even run **PHP** and software written in other languages using CGI-BIN.

Nowadays, modules for common programming languages like perl and PHP come directly attached to the web server, removing the significant performance hit that scripts executed using CGI-BIN suffer from.