What Is Rock

What is rock? I personally think rock is not just one obvious thing because there are multiple types of rock! To me I think rock is more of a feeling and attitude!! When you hear it you can get that feeling like you know it when you hear it! I do not listen to it on my own but if I am with someone and it comes on the radio or something I can tell it is rock by the way it sounds! And when you see someone who is big into rock or a part of it you can kinda tell by the way the look/dress and by the way they act!