Brian, Travis is right. A direct download will download a complete file, in this case the ISO image. A torrent file on the other hand is a file a bit torrent program will use to download a file bit's by bit's from different computers running the torrent program. These computers are called seeds. When the torrent program has all the bit's it reassembly's it into the ISO image. A seed computer can be either a server or a personal computer allowing others access to there file (ISO image). The key is you have to have a Torrent program installed on your computer.
GP if you want to deal with consent reboot's, viruses, malware, spyware, paying for all you applications then that is fine. Bill Gates appreciates your loyalty. I hate to bust your bubble but not all of NASA's computers run Windows, most of their servers run Linux, it is more reliable.