Do you need it or want it?

So.... I want to ask a simple thing. What's the difference of needs and wants?
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Okay. After attending my marketing lecture, I found out what those definition had in me for as long as I remember are wrong. My primary school (or kindergarten?) teacher had taught us in a wrong way.
Needs = something that is essential for living
Wants = something you crave for but not necessarily important. Therefore conclude want is not as important as need. As example, you have money, but you have to spend it on your needs rather than what you want that does not hold much meaning at all.

and, it's WRONG.

Need is state of deprivation including physical, social, and individual needs (okay, that's too deep, I'm just gonna rephrase it as the same as the one above there)
Want is form that human need takes, as shaped by culture and individual personality (taken from my notes, too hard to understand but I tried: is a form of what someone use to satisfy their need.)
Example: you have to eat, therefore a need for food. What someone from America and from Asia want to satisfy their hunger are different. Both need food, but American might wants burger or steak to satisfy the need while Asian might wants noodle or rice.

BOOM. My brain exploded right at that second. Mindblown.
How could I mistaken such a basic thing for my entire life?