How to run php programs on local computer?

[joe at actionline.com]

Keith asked:
> Did you install PHP and MySql ?  If so did you start both servers?


After I did the apache2 installation, it instructed me
to run a file in /var/www/ which I did and saw this result:

"It works! This is the default web page for this server.
The web server software is running but no content has been added, yet."

There was no other instruction. PHP was part of the apache2 installation.

AFAIK, I do not have any need for MySql, so I have not installed it.
Since the message above said "the web server software is running"
and no other start-up instructions were indicated, do I still need
to start the apache server?

Very confusing.