Time StepUsed to define the time interval between simulations, and in game engines it is used to reflect how often a function needs to be run.

Physics uses mathematical models to predict the future. These models output a path between the present and the future. When calculating the path, it is used to predict the future direction. The accuracy of the direction depends on the model input value (time). During the test, the lower the time value provided to the model, the more steps can be taken before the simulation reaches the goal. These time values are also called time steps or dt.

If a "step" is the process of calculating the next state of the system, then the "time step" is the time interval during which the simulation will proceed until the next "step".

References

【1】https://www.gamedev.net/forums/topic/673798-what-is-a-timestep/