Someone mentioned to me recently that they don’t know how to use bit torrents.  When there is a common and pervasive computer technology out there that we can’t really get a grip on, asking to have it explained can make you feel like an idiot.  For the wikipedia version of what bit torrent(s) is/are, please follow this handy link.  For a shorter, less detailed explanation, continue reading.

The principle at work is this: if you download a file from one place, you can only download it as fast as that place can upload it.  If it’s a file that a lot of people want, that place is going to need a whole ton of bandwidth.  However, if a bunch of people already have a copy of the file, you could really spread out that ‘upstream’ burden by taking a little bit from this guy, and little from this other guy, etc.  For really popular torrents, you have the potential to maximize your download speed without putting a heavy strain on any one uploader.

So when you download a .torrent file, what the hell is it? Again, without too much detail, this is a file that tells your computer who to connect to to get the content that you want.  For example, I downloaded a torrent of a Slackware linux distribution last week.  The torrent file was tiny, so it only took a second to download.  By opening it with a bit torrent client, I was able to connect to others that already have the file I needed, and I downloaded it in no time.

What do you need to use torrents? Like I said, you need a client in order to open a torrent file and download what you want.  This is really simple to think about if you equate it to POP3 (not web-based) email– if someone sends you a message, that message only exists in a file on a server unless you have a client program (like Outlook) that knows how to retrieve it.  So, you need a BitTorrent client in order to open those torrents.  On Windows and Mac, I think the easiest one to get and use is from BitTorrent dot com.  My Ubuntu system uses a client called Transmission by default.  Either way, it’s going to do the same thing: download by tracking to a torrent.

How long is this going to take? The speed that you get when downloading a torrent is going to vary based on how many people are uploading (or “seeding”) the file in question.  So depending on that, and the size of your file, it could take minutes or hours or days.

Where does the file go once it’s downloaded? This is going to depend on the settings in your bittorrent client.  Personally, I like things to be dropped right on my face, so I have my set up to put all torrent downloads on the Desktop.  But it’s something you might need to adjust with your individual software…

And this is illegal, right? It’s absolutely not.  Sharing files via torrent is actually (subjectively speaking) the most efficient way to disceminate data over the web– why download something a million times from one location and clog up one corner of the Internet when you could spread the traffic around?  Granted, there is a lot of illegal content being shared via torrent (copies of movies, TV, music, and pirated software), but there’s also a lot being shared that’s 100% on the up-and-up.

Hope this was a little bit helpful.  It’s definitely NOT an exhaustive or comprehensive discussion of how torrents work, but this should be enough to get you started.  Enjoy!