Okay ... engineers cannot write. I am an engineer and I accept that. I wrote yesterday's blog thinking I was explaining everything clearly. However, the look on my wife's face as she read the absolutely horrid sentence of "Once someone has completed downloading (even while they are downloading), you start uploading what you've downloaded to other people who are trying to download what you just got.", I began to think I may not have been as clear as I hoped. Then, when she said "okay? ... whatever ", I knew I had failed. So, if you read yesterday's blog, I found a page that explains How Bittorrent Works. If you still don't understand, then I can't help you. I'm an engineer, I build things like this, I don't explain them. That's why we have marketing and business teams.