So, OOP stands for Object Oriented Programming, OOP can be used in Roblox Lua to so I am going to show you how!
First off OOP Is basicly Vectors and Vector Math. There are 2 Types of vector, Vector2 and Vector3 and there are the 16int versions of them, but they aren't that important. Soo lets get started with each of these vectors!
Vector2: Vector2 Is the vector that locates the position of a object and they are used like these: Vector2.new(x, y) -- the x and y are the coordinates of the object
Vector3: Vector3 Is the vector that gets the size of a object, this vector can be used in many ways but its used mostly in tweening, and they are used like this: Vector3.new(size) -- size of a object
*note that this is just a simple tutorial and explanation of how Vectors work*