Nash equilibrium is a term used in game theory to describe a state where each player's strategy is optimal given the strategies of the other players. There are several synonyms for this term, including strategic equilibrium, non-cooperative equilibrium, and best response equilibrium. The concept of Nash equilibrium was first introduced by John Nash in 1950, and has been widely used in economics, political science, and other social sciences to analyze decision-making in situations where multiple players are involved. Another related term is the Pareto efficiency, which describes a state where no player can improve their outcome without hurting another player's outcome. Understanding Nash Equilibrium and its synonyms is vital for analyzing strategic decision-making in complex environments.