PHP $_GET
This is a 'superglobal' variable. This simply means that it is available in all scopes throughout a php script.
When you use form method as get the form values id available in $_GET variable as an array.
Example
<form action="test.php" method="get">
Fruit Name: <input type="text" name="fname" />
<input type="submit" />
</form>
On the next page you can use this code to display what you have entered in Fruits Name
Fruit <?php echo $_GET["fname"]; ?>


