Stokes’ Theorem relates the integral of a differential form over a manifold’s boundary to the integral of its exterior derivative over the manifold itself. Mathematically, Stokes’ Theorem can be formulated as follows:

The idea of integrate along tangent segment derivative = f(end point B) – f(end point A) is easy to understand, but moving up to one more dimensional – integrate along area curls = boundary difference, the boundary’s concept is very abstract to understand?!