Let me make it an analogy, an analogy between programs and recipes. A program is a lot like a recipe, each one has a list of steps to be carried out with rules for had to tell when you’re done or when to go back. At the end, there’s a certain result.
If you cook, you probably exchange recepies with your friends, and you probably change recipes too. And if you made changes and you like the result, your friend like eating it, then you may give them the change version of the recipe.
So imagine a world where you can’t change your recipe because somebody has gone out his way to set it up so that is impossible to change it. And imagine that if you share your recipe with your friends, they will call you a pirate and try to put you in a prison for years.