A Jedi was a member of the Jedi Order, who studied, served and used the mystical energies of the Force; usually, the light side of the Force. The weapon of the Jedi was the lightsaber, a weapon with a blade made of pure energy. The Jedi fought for peace and justice in the Galactic Republic, usually against their mortal enemies, the Sith and Dark Jedi, who studied the dark side of the Force.