What do integrals and derivatives actually do/mean?

Integrals are frequently used in computing areas in two, three and even multidimensional space, thus they can be used to find out the "area" or "volume" of objects that we cannot even draw. Practically, when we do the integral of a function we are computing the area of the space that lies "under" the funtion. Eg: uniform function = area of a square/rectangle
The derivatives show us the rate of change of a function, which means how much a function is changing at different points. This a very useful tool that is used in analysing functions which model (describe) different dynamics, as it shows us their maximum, minimum, and how fast they would grow or decrease. Eg: in physics the velocity is the derivative of the position function