You mean, the derivative of a function, as in calculus ?
If it's that, know that the mathematical concept of derivative was essentially invented to express a certain concept in physics: "change". Newton and Leibniz are considered to be its inventors.
"change of position with time" = velocity
Newton needed to write down velocity as a function of time, when he had position as a function of time. Hence his definition of velocity v = dx /dt
"change of velocity with time" = acceleration, a = dv/dt = d^2 x/dt^2
Acceleration is the second derivative wrt time, of position.
Newton needed that, to write his famous law: mass x acceleration = force
But the concept of derivative got also used in other ways. For instance, the ELECTRIC FIELD is (minus) the change of potential with position:
E_x = - dV/dx
Note that we now have a derivative towards space, not towards time. So the derivative concept is used further than just "change in time".
In modern physics, derivatives abound, in many ways...