You may have seen this iconic Star WarsTM weapon, it's basically a metal tube that projects a colored laser. It is extremely hot (plasma) and it can burn right through a lot of things.
Fantasy[]
The lightsaber, also referred to as a laser sword by those who were unfamiliar with it, was a weapon usually used by the Jedi, Sith, and other Force-sensitives. Lightsabers consisted of a plasma blade, powered by a kaiburr crystal, that was emitted from a usually metal hilt and could be shut off at will. It was a weapon that required skill and training, and was greatly enhanced when used in conjunction with the Force. Though also used by the Sith, the lightsaber was synonymous with the Jedi, with some in the galaxy believing only Jedi could use lightsabers.
Reality[]
Although in Star Wars media the lightsaber is an awesome metal hilt protruding a nuclear plasma blade, the reality could be anything but. The real lightsaber, made by Hacksmith Industries, is basically just a blow torch with a mini lightsaber hilt.