Need vs Want

We loosely know what they mean but always have hard time categorizing them. Copying from http://www.socialstudiesforkids.com/articles/economics/wantsandneeds1.htm 

A need is something you have to have, something you can't do without. A good example is food. If you don't eat, you won't survive for long.

A want is something you would like to have. It is not absolutely necessary, but it would be a good thing to have. A good example is music. Now, some people might argue that music is a need because they think they can't do without it. But you don't need music to survive. You do need to eat.

I have tried to put the above concept in a diagram and classified the red quadrants as type I & type II errors. Basically, you probably should not want 'things' that you don't need(Type II error) and also not say that you don't want 'something' even though you actually need it (Type I error, actually harder to identify).