# Introduction

Classes are definitions combining data (_otherwise known as `attributes`, `properties`,`data members`, `variables`, or `fields`_) with `functions` (_otherwise known as `methods`_).
Class definitions are used to create copies or `instances` of the `class`, commonly known as `objects`.
Objects can represent real world entities (_such as cars or cats_) - or more abstract concepts (_such as integers, vehicles, or mammals_).
Each object is unique in computer memory and represents some part of an overall model.
Classes and objects can be found in several programming paradigms, but are integral to [object oriented programming][oop] (OOP), in which programs are made up of objects that interact with one another.

[oop]:https://www.educative.io/blog/object-oriented-programming
