Concrete Class

PHP has abstract classes and methods: the contrary to abstract is concrete. This is the default state of a method or class, when it has a code block with implementation. It also has no specific keyword to designate it.

<?php
abstract class AbstractClass
{
    // Concrete method
    public function printOut() {
        print $this->getValue() . "\n";
    }

    // Method without an implementation
    abstract protected function getValue();
 }

?>

Related : Abstract Keyword