Hi guys,
This is my first post in this forum.
Recently i come across one interesting advantage of PHP that it is the simplest yet powerful language to communicate with linux .

However my knowledge of PHP is very weak.

Can u please guide me about following queries.
1)which version of PHP should i install on my linux machine.
2)I heard sometime php get installed while installing web server(correct me if i m wrong).
If it is already install how do i check the version of PHP?
3)How do i check web server version(Most probably i will be working on Apache web server).
4)How do i check MySql version installed in my machine?
If it is not installed in my machine which version will be best suited to communicate with PHP.

My linux machine specification is as follows.
uname -o
GNU/Linux
lsb_release -a
LSB Version: :core-3.0-ia32:core-3.0-noarch:graphics-3.0-ia32:graphics-3.0-noarch
Distributor ID: EnterpriseEnterpriseAS
Description: Enterprise Linux Enterprise Linux AS release 4 (October Update 7)
Release: 4
Codename: OctoberUpdate7
Thanks in advance.