This video provides a very brief introduction to object oriented programming. In short, object oriented programming involves adding functions to structs, which are referred to as "classes." Then objects can be created from those classes, much like instances can be created from structs. This video explains the basics of "structs with functions," and briefly covers some of the design decisions involved in writing object oriented programs. It also shows how to convert the procedural programming-oriented calculator from earlier into an object oriented implementation.
This video is part of a series of videos on an introduction to programming. This series will introduce basic programming concepts. The goal of this series is to get you familiar with these concepts so that you can begin making video games with a game engine, such as Godot. However, the series will also include some higher level concepts that are more useful for computer science and not necessarily directly relevant to game development.