Nash equilibrium

A Nash equilibrium is a strategy profile in game theory in which no player has a dominant strategy. Each player correctly anticipates the strategic choice of all other players, and thus has no incentive to unilaterally deviate from their own optimal strategy

source: https://builtin.com/data-science/nash-equilibrium

For example, suppose two friends wish to see a movie together but disagree on which movie. If both would rather see either movie together than see a movie alone, then both friends seeing either movie constitutes a Nash equilibrium, as neither can opt to see the other film without suffering a worse outcome.

source: https://www.britannica.com/science/Nash-equilibrium#:~:text=For%20example%2C%20suppose%20two%20friends,without%20suffering%20a%20worse%20outcome.