mysql setup on a server

[joeiscoolone]

I know that when you use php and mysql you have php on one server and mysql on another, so when you install mysql onto a server would you need linux and apache?

[gesf]

Both PHP and MySQL can be installed on the same machine.
They can also work under different platforms (Linux, Windows, etc) and using different HTTP servers (e.g.: Apache, IIS).

[vladimir_cz]

few years ago I develop application for stories server with heavy traffic.
there was 5 web servers (round-robin) and one mysql sever.
mysql server has 5 100Mb interfaces and these intrerfaces was connected to each of web servers peer-to-peer.
this system lives now (more than 5 years) and uses same techology (star)
5 years ago this servers set serve more than 70 000 unique visitors daily and more than 3 millon page view each day.

you should choose your configuration depending your requests, your grow plans and common sense, of course