Pseudo-variable

A pseudo-variable is a term used to describe a symbol that looks like a variable but does not represent one. Instead, it is a special case that has a specific meaning within its context. In PHP, $this is the only pseudo-variable: it represents the object that is called.

<?php

class x {
     private string $name;

     function __construct($name) {
             $this->name = $name;
     }

     function foo() {
             // $this represents any object of type x
             print $this->name;
     }
}

// $a represents only the object 'a', type x, until it is reassigned
$a = new x('a');

// $b represents only the object 'b', type x, until it is reassigned
$b = new x('b');

?>

Documentation

Related : Variables