The notation "7!" represents the mathematical concept of factorial, which is the product of all positive integers from 1 to 7. In this case, it means multiplying 7 by every whole number less than it down to 1. So, 7! = 7 × 6 × 5 × 4 × 3 × 2 × 1. Factorials are commonly used in various fields, including combinatorics, probability, and statistics. They help calculate permutations and combinations, which are essential for determining the number of ways to arrange or select items from a set.