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.
On the next page you can use this code to display what you have entered in Fruits Name
<form action="test.php" method="get"> Fruit Name: <input type="text" name="fname" /> <input type="submit" /> </form>
Fruit <?php echo $_GET["fname"]; ?>