In simple words, You are a Leecher/Peer until your download completes. You become a Seeder once you have 100% download.
Mostly, all of us are well known what torrent is and where we use it? But, What exactly is torrent? How does BitTorrent work?Why torrent? Is torrent legal? How are large files hosted on the Internet easily?
An American Computer programmer Bram Cohen came up with the concept of sharing a file over the Internet with different hosts. BitTorrent was first released by Bram Cohen back in 2001, but it took two years before the new file-sharing protocol gained a notable audience. In the years that followed millions of torrent files were downloaded and shared billions of times. Bram Cohen designed a peer to peer communication protocol for distributing data over the internet termed as BitTorrent protocol. Peer-to-peer file sharing is different from traditional file downloading. In peer-to-peer sharing, you use a software program (rather than your Web browser) to locate computers that have the file you want.Because these are ordinary computers like yours, as opposed to servers, they are called peers.The BitTorrent protocol divides a large files into small chunks allowing users to download sections of it and to exchange the sections between themselves until the file download completes. This protocol uses less bandwidth from the file's creator. This is a great advantage for its distribution in the long term.
How does BitTorrent work?
Unlike some other peer-to-peer downloading methods, BitTorrent is a protocol that offloads some of the file tracking work to a central server (called a tracker). Another difference is that it uses a principal called tit-for-tat. This means that in order to receive files, you have to give them. With BitTorrent, the more files you share with others, the faster your downloads are. Finally, to make better use of available Internet bandwidth (the pipeline for data transmission), BitTorrent downloads different pieces of the file you want simultaneously from multiple computers.
Its a fairly simple concept, When you download a torrent, you aren't downloading the file from one specific person, but rather from many different sources who share the file, for example; lets say I am downloading a movie from a torrent thats around 300 megabytes, at 200 kb/s speed from 10 different sources, that would mean that the average transfer rate per person is 20 kb/s, so from each person you are downloading the same file (but different pieces of it) at an average 20kb/s.
The thing is that some people have slow Internet, so you made download faster from others, lets say you have 10 different sources but 5 of them are on dial up, and you only receive a max of 5 kb/s, that means the other 175 kb/s would come from the other 5 Internet users who may be using broadband or higher.
Its the same concept for seeding, once you download the file, and you allow to seed it, a lot of people are connect to your computer since you are hosting the file, not just one person, lets say you are seeding a file for 30 people, but your upload speed is at 150kb/s each of them are receiving an average of 5 kb/s upload speed for each person.
Your friends Internet connection impacts the speed of the download, and also He may be getting unlucky and downloading from sources that have slow Internet speeds, (it happens)
Is torrent legal?
As long as the item is copyrighted and you don’t own it and if someone else is the owner then downloading it for free is not legal. But via torrent it is legal. The protocol itself is perfectly legal. Torrent may be primarily used for privacy at the present mainly because of its decentralized nature. However there are many legal uses of BitTorrent, like many Linux distros prefer torrent to push out updates as it reduces the stress on their servers.
What is seeding?
Seeding is where you leave your BitTorrent client open after you've finished your download to help distribute it (you distribute the file while downloading, but it's even more helpful if you continue to distribute the full file even after you have finished downloading). Chances are that most of the data you got was from seeds, so help give back to the community! It doesn't require much - the client will continue seeding until the torrent is removed (right click the torrent, then hit Remove). Proper practice is to seed until the ratio of upload:download is at least 1.00.
What are seeds, peers and leeches in Torrents' language?
SEEDERS are those who has downloaded the file already or initially only one person who uploads the torrent seeds to others. You may notice that after your download is complete the torrent turns from DOWNLOADING to SEEDING. Seeder is someone from whom you can download a piece of file. Hence they affect the overall availability of file on P2P (Point to Point) network.
PEERS are those who are downloading and uploading at the same time. They do not posses the whole file. They only posses parts of whole. Peer is someone who is involved in file sharing activity. It is a generic term.
LEECHERS are those who don’t have all parts file and are not able to share you the required part of the file. If there are zero seeders it is doubtful that you will ever finish downloading that torrent. Very rarely you can download the whole only by leechers. Leecher is someone who has downloaded a file but is not sharing it back to P2P (Point to Point) network. Hence, overall availablity of file decreases.
In simple words, You are a Leecher/Peer until your download completes. You become a Seeder once you have 100% download.
What is their inside Bit-torrent file?
The address to one or more trackers and information about the files. The tracker is a server that knows which users have the real file.
The basic principle is:
- Your BitTorrent program, that opens the BitTorrent file, connects to the tracker(s) and gets a list of people who have the file.
- Your BitTorrent program connects to the people and request pieces of the file.
- You are now also on the list, so any user opening the BitTorrent File after you will get your address as well and can download the pieces from you that you already have downloaded.
How the first seeding starts in torrent?
- You create a torrent using any torrent client
- add trackers (to manage a list of all the swarms and peers)
- distribute the .torrent file
- users (torrent clients) read the .torrent file and then obtain a list of peers and seeders from the trackers by querying the unique hash of that torrent
- Before the connections are made to those peers, various information like: total pieces, piece size, names, hierarchy of files etc are saved from the .torrent file
- connection setup and downloading starts
What is the first seeded torrent file?
The Oldest Torrent
The torrent file that has been around for the longest time according to our knowledge is
The Matrix ASCII. We already crowned this one the oldest torrent back in 2005, and as of today(Nov 7, 2010) it is still active with a few downloaders and only one seeder.
The
torrent file in question was created in December 2003 when sites like isoHunt, The Pirate Bay and
Torrentz.com were only a few months old and when Facebook and YouTube didn’t yet exist. Thus far, this torrent has survived a mind boggling 2500 days.
What is the largest torrent file?
When we refer to the largest torrent we mean the single .torrent file that downloads the most data, not the size of the .torrent file itself. There are several huge torrent files active at the moment, but the record goes to a torrent with a 746.70 GB collection of all 2010 World Cup soccer matches (~ 6GB per half).
Refrences:
(denoted in dirac notation ). But unlike classical bit a qubit can be in more than two possible states. That is, it can be in a superposition of states 
and 
is the probability amplitude for state 
both can be complex numbers. Since 
Hello, my name is Jack Sparrow. I'm a 50 year old self-employed Pirate from the Caribbean.