What does an electron cloud show?

Answer 1

That depends on how it's drawn. It may give some idea of the probability of finding an electron in a given location, or it may just show the region of space where the electron is likely to be found. If it looks like a bunch of individual dots, the density of the dots gives some indication of the probability (the closer together the dots are in a region, the higher the probability of finding the electron in that region). If it looks like a solid object (or a collection of solid objects), it's just the region(s) where the probability is over some value.