What is the difference between permutations and combinations?

Question

What is the difference between permutations and combinations?

In: 25

Answer 1

Permutations are ordered, combinations are not.

Lets say you have the letters {A, B, C, D, E} and you want to make a subset of three of them.

In permutations, the set (A, B, C) is considered to be distinct from (B, C, A) and (C, A, B). Wheras in combinations, all three are considered to be the same.

So using this example of a three-element subset of a five-element set, there are 60 possible permutations, but only 10 possible combinations.