I received an email question today, and I figured other non-geek people might be wondering the same thing. I decided to post it here in hopes it helps others. Feel free to comment / make any corrections to my answer.

I recently read an article about bit-torrents and tried finding more information about them without much luck, so I decided to go to the Apple store … and ask them. When I asked one of the Apple people about bit-torrents she did not seem very thrilled to be talking to me anymore and said that she was unable to discuss the topic with me any longer. Do you have any information about bit-torrents you could share with me? That is other than that it is pirating tv or movies? Do you know if there is a chance of downloading a virus or something that could potentially do some harm to my computer?

Yeah, I can imagine Apple would have a policy to not talk about it. What it is, basically, is a way to transfer huge files over the internet by sending small chucks of the file to lots of different people. Then, when you download the file, you are downloading it in small parts from many different sources.

By downloading the file in the bit torrent way, you can download the file faster and more reliably. Faster, because you can download parts of the file at the same time from different places, and more reliably because if one part fails you just need to re-downlod that one part.

A real world example is, you can either have one person go pickup a heavy box and move it, or you can have 30 people take the contents out of the box and move it then put it back together when you get there. If that makes any sense.

Some people get upset about bit-torrents because since it’s used to move huge files around, you’ll find a lot of software and movies on bit-torrent aggregators. This is only because bit torrent is good at moving around big files, and movies and software are generally big files. There is nothing bad about bit-torrent, but some people assume you are doing copyright infringement when you talk / ask about it.

Bit-torrent, by the way, is just a file format / specification. So, you would “download a bit-torrent file” for example. The things that some people think are “bad” (depending on your point of view) are aggregators. They are like Google for bit-torrents. The most talked about example being the pirate bay: http://thepiratebay.org/.

To download any bit-torrents, by they way, you’ll need a bit-torrent client like http://www.transmissionbt.com/

Bit-torrent in itself it not bad or virus ridden – in fact it’s really useful for downloading things like Operating Systems. It does have a bad stigma around it though, and if you download shady or “stolen” software you’re asking for trouble no matter if you download it with bit-torrent, a normal download, or off a CD.