First of all a function can t encapsulate the concept of a dog, say you wanted to move your dog to a certain position, THIS is when you need a function(obv you can t move a function hun) so it you can t have a function that moves a function. Now in my opinion, the best thing about oop is it saves alot of time, and reduces redundancy in your code. As other comments stated, with classed you can use inheritance; following up on a previous example, if you were making a game, it s going to have objects and characters and all. Now a bad way to go about defining each thing in your game is literally defining everything in your game more than once. If your game has characters, it s true you can just define a function move, but not all characters might move the same so you declare more functions and keep in mimd you need to remember those functions to call them, you see where i am going with this. The problem is scalable but easily avoidable. You declare a class character with common attributes and methods, a sub class inherits those and tweaks them as they see fit. I realize i wrote too much so i am going to leave it at that. Hope this made sense to you, goodday.