Absolute Name

An absolute name is a name that is independent from the current namespace. It is usually identified by the leading \ sign.

The opposite of relative name is relative name.

<?php

namespace A {
    function B() {}

    class C {}

}

namespace B {
    //absolute name to call a function
    \A\B();

    //absolute name to create an object
    new \A\C();
}

?>

Documentation

Related : Import, Relative Name, Namespaced Name