For this tutorial it is reccomended you have access to a PHP host or server, if you wish to try any of the examples.
Variables hold data, thats all. They are not an impressive function, or nor do they require excellent PHP skills they are there to hold data you may need again. For example,
<? echo 'Hello Woody';
echo 'Howdy Woody';
echo 'Was up Woody?';
echo 'l8r Woody'; ?>
$who = 'Woody';
The $who is the name of the Variable, by using $ PHP knows we are creating a Variable, the = sign is what the Variable contains, and between the ' are the Variable contents, Simple?
If we want to echo our welcomes to Woody we could use
echo $woody;
Here is a full example
<?
$who = 'Woody';
echo 'Hello '.$who.'';
echo 'Howdy '.$who.'';
echo 'Was up '.$who.'';
echo 'l8r '.$who.'';
?>
Now you should have an understanding of how to create a Variable, and how to echo them.