From 1:

In physics, action is an attribute of the dynamics of a physical system from which the equations of motion of the system can be derived through the principle of stationary action. Action is a mathematical functional which takes the trajectory, also called path or history, of the system as its argument and has a real number as its result. Generally, the action takes different values for different paths.

Mathematical formulation, via the Lagrangian (see Lagrangian mechanics:)

$$S=\int dt L(q,\dot q)$$

1

Wikipedia contributors. (2021, March 9). Action (physics). Wikipedia. https://en.wikipedia.org/wiki/Action_(physics)

09:45 Monday 16 August 2021