HUH?

I must say, somethimes I am given assinments about things that I know NOTHING about.
This time is one of them.

What in the world, may I ask, is plasma cutting?!?

Normally, if I was really interested in the product itself, I would go on the site and do the research. Today isn't one of those days. So, I'm going to allow you all to do it for me. All you have to do is click on the underlined link above, in my question, where it says "plasma cutting", and then you can explain it to me. I just can't bear to do it myself today. Just not in the mood! Thanks for your help!!!