Paradigm refers to the style. Functional programming, object oriented programming, and imperative programming are 3 of them. Lua’s compiler just works better with imperative by a slight margin because of it being friendlier to how the language is built.
Imperative is just statement after statememt that changes what the program is doing.
Functional is an immutable state which the program interacts with using predefined function logic.
Object oriented involves each state having its own class behavior.
You could really use them interchangeably, but they do have their own strengths. Imperative is straight forward and good for dictating stuff like game logic, while functional is arguably better for building readable data oriented systems, and object oriented is usually for keeping track of actual entities and how they behave.