# What is the difference between a function and a map? [duplicate]

Possible Duplicate:
Is there any difference between mapping and function?

I am an aspiring mathematician who just started out. What is the difference between a function and a map? Or are these notions equivalent?

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## marked as duplicate by Micah, Hagen von Eitzen, Chris Eagle, MJD, ThomasDec 10 '12 at 22:04

@glebovg, "function" has a precise definition: A function from a set $A$ to a set $B$ is a subset $f$ of $A \times B$ such that for any $a \in A$ there exists a unique $b \in B$ such that $(a,b) \in f$. In this notation, you would denote $b$ by $f(a)$ and the point is that a function is completely determined by its graph. –  Santiago Canez Dec 10 '12 at 21:39