What is a torrent?

[ThunderHappens]

I'm very behind with online technology, and have only recently heard of torrent files. I have no idea what they are exactly, and how they work.

I really want one of the Unleashed show files from dimeadozen.org recently posted on the Rumours board.

Would someone be so kind as to explain to me in simple terms how this works and what I need to do?

Sharing info online still scares me, and this process seems rather "invasive". From what I gather, it seems that I'm accessing someone else's computer, and then others would access mine....is this true?

I'm paranoid, I know....but I would love to have a recent Mac concert to watch over and over.

Any help would be very much appreciated!