The stable marriage problem is a mathematical concept that seeks to find a stable matching between two equally sized groups, typically referred to as men and women. Each individual ranks the members of the opposite group based on their preferences. A matching is considered stable if there are no two individuals who would prefer each other over their current partners. The problem was first formalized by David Gale and Lloyd Shapley in 1962. They developed an algorithm, known as the Gale-Shapley algorithm, which guarantees a stable matching. This concept has applications in various fields, including economics, computer science, and game theory.