An arrangement of a set of items or events in which the order does not matter?

The term for an arrangement of a set of items or events in which the order does not matter is called a combination. In mathematics, combinations are calculated using the formula C(n, r) = n! / (r! * (n - r)!), where n is the total number of items and r is the number of items being chosen. Combinations are used in various fields such as probability, statistics, and combinatorics to analyze and solve problems involving unordered selections.