In this equilibrium, each player in the game is convinced that given the strategic decisions of other players, he chooses the optimal strategy to respond to the opponent's strategy. This equilibrium is conditionally optimal, while the dominant strategy equilibrium is unconditionally optimal. Proper subset whose dominant strategy equilibrium is Nash equilibrium.

The application of Nash equilibrium is mainly a strategic choice between oligopolistic manufacturers. You can look at the business war stories between famous business tycoons, such as Coca-Cola and Pepsi, Unilever and Procter & Gamble. G, Microsoft, Apple, Google, etc.