What is it? Wat is all this electricity nonsense?
Step 1: Electrons!
Atoms (the stuff that makes up stuff) have a nucleus; a hard center which determines the atom's weight and properties. This nucleus is made of both positively charged protons and charge-less neutrons. Spinning around that nucleus at near the speed of light are clouds of electrons; particles with a negative charge. Normally the atoms have an identical number of electrons and protons, and because of this atoms typically have a net charge of 0. However, these electrons can be removed or added leaving the atom charged either charged positively or negatively, respectively.
Atoms don’t like to be charged however and they do their best to become neutral. Metals tend to allow their electron clouds to be modified easily, and when you add one electron to a metal atom's cloud another one jumps out into a neighboring atom's cloud. This bumps another electron out of that cloud and a chain reaction is put into place. An electric current is now formed in the conductor, and it will continue until a bumped electron hits a positively charged atom and fills the "hole" in that atom's cloud. This flow from negative to positive is called electricity.