Permutations express themselves in the versatility of a representation or the processing of program steps of a program.
For digits, the permutation is the number of possible representations in which several digits can be represented. For two numbers, there are only two possible representations: Either the first number is in front or the second. Three numbers, assuming the numbers 4, 6 and 8, can be represented in six different permutations: 468, 486, 648, 684, 846 and 864. The number of permutations corresponds to the factorial (!) of the elements. 3! (factorial of 3) means 1 x 2 x 3, so 6. 4! is 12, 5! is 120.