I'm trying to get a better understanding of when to use Gauss's Law and I would appreciate any help. I know so far that it can be easily used in cases of high symmetry and infinitely long charged objects. Does it matter if the surface is conducting or insulating? If I have, for example, a sphere where I'm trying to find the electric field at several radii inside the sphere AND outside the sphere, would it matter if the sphere was a conductor or an insulator when I apply Gauss's Law (which I'm assuming is correct since a sphere is symmetrical)? Could I sum it up as saying that point charges and finite length objects need Coulombs Law to find the electric field, whereas infinite objects and extremely symmetrical objects need Gauss's Law? Thanks for any help.