"Describe all functions \(\displaystyle f\ : \ A \ \right \ B\) where \(\displaystyle A=\{1, 2, 3\}\) and \(\displaystyle B=\{a, b\}\)".

After which we're going to debate whether or not each function is injective and/or surjective. But my real problem is that I don't know how to describe all the functions.

Thanks in advance!