How Torrent work and full detail about it

Torrent is a software which allow the users to download a file in a decentralized way. There are many softwares which are using torrent service like uTorrent, BitTorrent etc.

But we need to understand what is decentratlized or we can say that what is peer to peer (P2P) systems.

There are three types of systems:

• Centralized
• Decentralized
• Distributed

We only need to understand decentralized. So, a decentralized network has no central server (command and control centre), which means that it can operate with freely running nodes alone (P2P).

So lets see with example, A file name abc.mkv is on a multiple computers which are uploading them using torrent software like BitTorrent. You download an abc.torrent from the internet and open it in BitTorrent. BitTorrent just downloads it from these computers which are uploading it. This file will download in a chunks from the different computers without having the central server. If your one computer is shutdown, the file will still downloading from the other computers. But in case of server, if your server is down, you can't download a file from the server. So, without having server, you can easily download a file.

So, Expensive server equipment isn't necessary to send files to many people at once, and people has slow internet can just as easily download large sets of data because the file is not uploaded on a server but on the computers which are acting as server. 

The torrent file can download from two things: the .TORRENT file or a hash of the torrent, called magnet link. Magnet link has all the information of file on the torrent network same as torrent file

Torrent can be dangerous because if the file is downloading from the untrusted source, it can download the malware in your computer. Torrent can be use for piracy.

Common term on the torrents are:

Seed is the number of people sharing the file. Zero seeds means no one have full file and nobody can download the file.

A peer is someone downloading the file from a seeder.

Leechers only download the file. A leecher might instead upload nothing at all after the full file has been downloaded.

Swarm is a group of people downloading and sharing the same torrent.

Tracker is a server that tracks all the connected users and helps them find each other.

Client is a program or web service used by a torrent file or magnet link to understand how to download or upload files.