PERL and Apache mod_perl

What is the difference between PERL and Apache's mod_perl? My understanding is that mod_perl os precompiled for faster execution, but how does one go about doing that? Is it just installing a module, then the first time a script is run the compiled version becomes available? Or is there a precomiler you need to have to implement this?

tia

Can anyone enlighten me? Thanks

Don't know much about it --looks interesting. Ironically I was reading about it last nite when looking for info about Apache.

Some links:

http://perl.apache.org/start/index.html

http://perl.apache.org/docs/1.0/guide/getwet.html

http://perl.apache.org/download/