Every programming language has functions. You make 'em, you call 'em, you yell at them, and more. These properties are reminiscent of children in our physical world; and like children they are little bags of potential that can change your world.
Functions make things easy in programming. This is a rare and wonderful thing when it comes to a field that largely results in one scratching their head and pondering when trying to solve a problem. Think of them as mallaeble legos you can form into the strangest of things for whatever unique purpose you need. But, like having children, sometimes it is not the best call to declare a function out of nowhere. We won't get too far into the specific use-cases here. This is to be a guide on syntax, not best practice (that comes when we're pro as shit later).