The Apache Common Gateway Interface (or CGI) handler is the core component in Apache that links incoming HTTP requests from users to the CGI Perl scripts you have developed.
There are several implementations of CGI in Apache, and you can dynamically install each one into an Apache server using a shared-object file. The simplest interface, mod_cgi, provides the most rudimentary conduit for launching an instance of Perl for each CGI request.
More complex interfaces, such as mod_perl, actually embed the Perl interpreter directly into Apache, this increases the speed of Apache and Perl when serving CGI requests. For more information about
mod_perl, see Chapter 23.
The core ...