Any variables inside a " quoted string will be parsed. Any variables in a ' quoted string will not be parsed, and will be shown literally as the variable name. For this reason, ' quoted strings are very slightly faster for PHP to process.
$test = 'hello';
echo "this is a $test"; // returns this is a hello
echo 'this is a $test'; // returns this is a $test
I'd say use ' quotes unless you want variables inside your strings.
