$variable = "me"; //This is a string value
$variable = 1; //This is a Boolean value
$_GET && $_POST are called GLOBALS
so you can access them by
$_GET['key_name'];
IE:
echo $_GET['key_name'];
all things GLOBAL are with in an array/is an array so you can
print_r($_GET);
print_r($_POST);
or
foreach($_GET as $key => $value){
echo $key . ":" . $value . "<br>";
}