Lovely! You've probably already heard that electrons are the negative part of an atom; where as, the protons are the positive and neutrons are the peacekeepers :P. An atom is composed of protons and neutrons bunched together in the center while the electrons orbit them. But to the matter at hand... An electron's primary purpose is to provide stability. Electrons are the only atomic substance that can travel between atoms. Every atom desires stability, but electrons are the ones that aquire this by leaving atoms with a negative charge and goto an atom with a positive charge. (To picture this, imagine small magnets in space. The electrons will attract to the protons but can only get so close before the other electrons push eachother away.) Without electrons, there would be no atomic activity and the world would be dead...or find some other scientific way to work. A simple example would be hydrogen and helium. (H and He). Hydrogen has but one electron in it's original orbit and will always want to gain one electron to fill it's first orbit (first orbit supports 2, second supports 8) or perhaps lose it's one electron to an atom that desires it more. Helium, however, has both electrons in it's first orbit, and will never lose or gain electrons (considered a noble gas). I hope I didn't leave anything out.