Inheritance is one of the core concepts of object-oriented programming (OOP) languages. What is Inheritance? Inheritance is a mechanism in which one class acquires the property of another class. The capability of a class to derive properties and characteristics from another class is called Inheritance. In object-oriented programming, inheritance is the mechanism of basing an object or class upon another object (prototype-based inheritance) or class. PHP - What is Inheritance? Inheritance in OOP = When a class derives from another class. As with the other principles of OOP, inheritance is meant to optimize the work of programmers.