Whether you’ve never used it or you use it every day, it might be helpful to know exactly how this protocol allows you to download large files fast, using very little bandwidth. By the way it’s free, and doesn’t use spyware.
Here’s how it works: BitTorrent gathers pieces of the file you want and downloads them a variety of people who already have them, all simultaneously. This increases transfer speed, making it so you can transfer TV shows and music faster than you can with any other protocol.
But how does that work so much faster than what people normally do? Well we can start answering that question by talking about traditional client-server downloading.
According to traditional systems, when you open a web page and download a file from it onto your personal computer, the web browser software on your computer communicates with the server responsible for the web page and requests that that server transfer to your computer a copy of the file you requested. That transfer is then handled by a protocol, which is just a series of tasks that determine how things are done, and may be in this case the File Transfer Protocol or Hypertext Transfer Protocol.
How fast your computer can then receive and download the file from the server is determined by the amount of traffic the server has already been dealing with as well as the protocol type chosen and the number of computers that are also attempting to download the file. If the file is large and popular (like the most recent episode of Game of Thrones or whatever), it’s going to take a lot longer to download it.
BitTorrent doesn’t work that way, because it utilizes a process called peer-to-peer sharing as opposed to client-server downloading. Peer-to-peer file sharing allows for users to use a software program to locate nearby computers with the files they want. Their web browser plays no role in finding and downloading the file. Once the software is obtained, you can use it to send out a request for the file you want to download. The software then contacts other computers connected to the internet with the same software downloaded on them. When your software locates the computer with the file you want, the download begins. Others using the file-sharing software may then obtain files they want from your computer’s hard drive.
BitTorrent does use a server called a tracker to help with some of the file tracking work. It also uses something called tit-for-tat, which means that you cannot receive files without giving them. This became necessary once a phenomenon called leeching became prevalent among BitTorrent users.
File-searches and transfers from your device to that of other users can cause bottlenecks because some people may download files and then disconnect, refusing to allow others to obtain files from their system. This is called leeching and is pretty prevalent; people seem to think it’s safer to do this. It limits the amount of computers that the software has available when it searches for a requested file.