OK so I took my multivariable calculus class last year and at that time, when we learned about flux I understood it as the sum of the outward facing components of every vector generated by a vector field at every point on a surface. F dot N integrated over the surface area of the surface. I took this to represent things such as fluid flow accross a surface (the purpendicular components of the fluid's velocity at points on the surface summed over every point on the surface would provide the net velocity with which fluid entered or exited the surface). Recently, however, I have been reviewing this and other topics for a physics course and I realized that flux would actually represent the sum of every purpendicular component multiplied by an infinitesimal surface area element dsa. I haven't a clue what this could represent physically. Could anyone help me out? Also if anyone could shed some light on what electric flux represents that would help as well.