State is just values which are not considered to be variable function inputs - in other words each time you change state you have new functions. For example f(

State is just values which are not considered to be variable function inputs - in other words each time you change state you have new functions. For example f(x, y) = xy and then defining a differentiable function g(x) = f(x, a). You can imagine “a” being a state variable.