Rank 3 permutation group

A permutation is when you switch things around in a certain order. If you have three things, you can switch them around in different ways. When you have all the possible ways of switching three things around, we call it a rank 3 permutation group. It's like having a toy with three interchangeable parts that you can switch around to make different combinations, just like changing the order of letters in a name like "Bob", "BoB", and "BOb". The rank 3 permutation group is like having all the possible combinations of those parts. It's a set of all the different ways you can switch around those three parts.