A power set is a mathematical concept that refers to the set of all possible subsets of a given set. For any set A, the power set includes every combination of elements from A, including the empty set and A itself. If A has n elements, the power set will contain 2^n subsets. For example, if A = 1, 2, the power set of A is ∅, {1, 2, 1, 2}. The power set is denoted as P(A) or 2^A. Understanding power sets is essential in fields like set theory, combinatorics, and computer science.