The expression "5!" represents the mathematical operation known as factorial. Factorial is the product of all positive integers from 1 up to a specified number. In this case, "5!" means multiplying 5 by every whole number less than it: 5 × 4 × 3 × 2 × 1. Calculating "5!" gives us a total of 120. Factorials are commonly used in various fields, including combinatorics, probability, and statistics, to determine the number of ways to arrange or select items. For example, "5!" can help find the number of ways to arrange 5 distinct objects.