What type of PHP5 shall I install to learn PHP5 together with Apache, Please specify the Apache type too Since There are Two Apache types also

[Varuna Seneviratna <varunawithphp@xxxxxxxxx>]

I am Using Ubuntu 11.04 Desktop as my OS.Below are the two types of
PHP5 available for installation

php5 - server-side, HTML-embedded scripting language (metapackage)
php5-cgi - server-side, HTML-embedded scripting language (CGI binary)

I got the above by running the command "apt-cache search PHP5
1 What is the difference between the two.
2 What shall I install to learn PHP with apache(Please specify the
apache version too since there are two types available for Ubuntu)
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VS