Lightsabers are beams of pure light. **WARNING**: Do not swing at any at any part of your body you want to keep intact.**
A lightsaber is a beam made of pure energy. The thing with lightsabers is that they're pretty damn hard to get a hold of in reality unless you're tripping on acid, so you don't want to swing it around in your fucking house. If you do, you may (read: certainly will) break a lot of your childhood memories. Proper useage would be more like this: if somebody bullied you as a child, then disguise your deathstick as a flashlight. Then...
WHO'S THE NERD NOW, BITCH?!
Or you can make friends with him and do a dance that involves singing birds and rainbows. Depends what kind of person you are, really. A badass embodiment of retribution, or Dick Van Dyke.
Apparently the side of the Force you're on is reflected in the color of your lightsaber. If you're on the dark side, you get red, congratulations. If you're on the light side, you get pretty much every other color in the visible spectrum except red. Either way, you have a goddamned lightsaber.
In addition to lightsaber color, there are many other things that affect you depending on what side you're on. If you're on the dark side, you end up looking like a rotten cabbage. On the other hand, the people fear you, and the downside is that if you have no power, you end up ordering your groceries online.
Think about it, this could be you.
If you choose the light side, you get the ability to grow a badass beard. The downside is that you have a very strict set of rules, which includes: no sex, no relationships. However, you are loved by everyone and are recognized as a great hero from a famous sci-fi movie trilogy.
In summary: The deathstick can be a powerful and dangerous thing, influenced by your side of the Force, your motivation, whether or not you're Samuel L. Jackson, and whether or not you're just going to use it to cut bread.