How do tags work?

[Moh]

How exactly do you use tags?

So if you was on a page tags?tag=lol how would it select all the other entries with the exact same tag as "lol".
So for the entries, the tags could be:

lol, funny, fail, kewl

funny, strange, lol

rofl, lol, pmsl

I know you use arrays, but to get the tag results, you have to use:
$array[0]
$array[1]
$array[2]
$array[3]
etc..

[WhatYouSay]

Do you mean, for example, loading a group of check-box's into an array?
Form:

<form action='submit.php' method='post'>
<input type='checkbox' value='1' name='lol[]'> (Notice the [] in the name)
<input type='checkbox' value='2' name='lol[]'> 
<input type='checkbox' value='3' name='lol[]'> 
</form>

PHP:

<?php
$movezig=$_POST['lol'];

//$movezig is now an array containing the values of the check-box's that are checked

?>