Ok friends, let's start from the beginning right? What is object-oriented programming?
The idea behind Object-Oriented programming is that you create a blueprint for the look of your "object" and call it over and over again to do whatever you want with it. Sounds helpful right? Well, it is. Every time you want to use an object, you must first create it so that it exists, and then configure its properties to use the attached functionalities. These functionalities are known as 'methods'. For example, a User object may have a get user details (in the form of a method) functionality attached. As you can see in theory is a really clear idea.
Thank you for reading! :)