The Axiom of Power Set says that if you have a set, you can make another set out of it that includes all the possible subsets of the first set.
Think of it like having a box of toys. You can make another box of toys out of the first one, and this new box will have every possible combination of toys that can be made from the original box.
So, if you have a set of letters: A, B, and C, the power set of that set would be a new set that contains all the possible combinations of those letters: {A}, {B}, {C}, {A,B}, {A,C}, {B,C}, and {A,B,C}.
This is a very useful tool in mathematics because it helps us understand the relationships between different sets and shows us all the possible outcomes that can occur.