Permutation and Combination are both an important concept in mathematics, but there are some differences between the two. Permutation simply refers to how objects, symbols, and values are arranged or selected in a particular sequence or order. The combination also refers to how values or symbols are selected, but their order or sequence is not needed or required.
The selection of objects is usually made by considering some underlying similarities between the object. For example, the right combination of letters A, B, C could be ABC, BCA, CAB, BAC, ACB, and CBA. This simply means the three letters can be combined in six different ways.
However, let's assume you have BAC as your locker combo. There are no other combinations that you can use to open the locker except if you use BAC. This is what permutation means because it follows a particular order. In other words, permutation can be regarded as an ordered combination.