True. But it's generally only common with older C-based languages where the goal was packing as many features as you can instead of high level design aimed to guard software from inexperienced overeager devs.

Yes, it's functions vs methods. You can make this explicit like in Python, you can make it implicit but have two kinds of methods, instance methods and static methods like in C++/C#/Java.

And you have JavaScript were all functions have an implicit this ...