This is a
glossary
A glossary (from grc, γλῶσσα, ''glossa''; language, speech, wording) also known as a vocabulary or clavis, is an alphabetical list of Term (language), terms in a particular domain of knowledge with the definitions for those terms. Tradi ...
of
jargon
Jargon is the specialized terminology associated with a particular field or area of activity. Jargon is normally employed in a particular Context (language use), communicative context and may not be well understood outside that context. The conte ...
related to
peer-to-peer file sharing
Peer-to-peer file sharing is the distribution and sharing of digital media using peer-to-peer (P2P) networking technology. P2P file sharing allows users to access media files such as books, music, movies, and games using a P2P software program tha ...
via the
BitTorrent protocol.
Terms
Availability
:(Also known as distributed copies.) The number of full copies of a file (or set of files and directories) directly available to the client. Each seed adds 1.0 to this number, as they have one complete copy of the file. A connected peer with a fraction of the file available adds that fraction to the availability, if no other peer has this part of the file.
:''Example:'' a peer with 65.3% of the file downloaded increases the availability by 0.653. However, if two peers both have the same portion of the file downloaded - say 50% - and there is only one seeder, the availability is 1.5.
:Sometimes "distributed copies" is considered to be "availability minus 1". So if the availability is 1.6, the distributed copies will be 0.6 because it is only counting the "copies" of the file.
Choked
:Describes a
peer to which the client refuses to send file pieces. A client ''chokes'' another client in several situations:
:* The second client is a ''seed'', in which case it does not want any pieces (i.e., it is completely ''uninterested'')
:* The client is already uploading at its full capacity (it has reached the value of
max_uploads
)
:* The second client has been
blacklisted
Blacklisting is the action of a group or authority compiling a blacklist (or black list) of people, countries or other entities to be avoided or distrusted as being deemed unacceptable to those making the list. If someone is on a blacklist, t ...
for being abusive or is using a blacklisted BitTorrent client.
Client
:The program that enables
peer-to-peer
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer n ...
file sharing
File sharing is the practice of distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books. Common methods of storage, transmission and dispersion include r ...
via the BitTorrent protocol. See
Comparison of BitTorrent clients
The following is a general comparison of BitTorrent clients, which are computer programs designed for peer-to-peer file sharing using the BitTorrent protocol.
The BitTorrent protocol coordinates segmented file transfer among peers connected in ...
.
Distributed Hash Table
:
Distributed Hash Table
A distributed hash table (DHT) is a distributed system that provides a lookup service similar to a hash table: key–value pairs are stored in a DHT, and any participating node can efficiently retrieve the value associated with a given key. The m ...
s (DHT) are used in Bittorrent for peers to send a list of other seeds/peers in the swarm for a particular torrent directly to a client without the need for a tracker.
Downloader
:A ''downloader'' is any peer that does not have the entire file and is downloading the file. This term, used in
Bram Cohen's Python
Python may refer to:
Snakes
* Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia
** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia
* Python (mythology), a mythical serpent
Computing
* Python (pro ...
implementation, lacks the negative connotation attributed to ''leech''. Bram prefers ''downloader'' to ''
leech
Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodie ...
'' because BitTorrent's tit-for-tat ensures downloaders also upload and thus do not unfairly qualify as ''leeches''.
Endgame / Endgame mode
:Any applied algorithm for downloading the last few pieces (see below) of a torrent.
:In typical client operation the last download pieces arrive more slowly than the others. This is because the faster and more easily accessible pieces should have already been obtained. In order to prevent the last pieces becoming unobtainable, BitTorrent clients attempt to get the last missing pieces from all of its peers. Upon receiving the last pieces a cancel request command is sent to other peers.
Fake
:A fake torrent is a torrent that does not contain what is specified in its name or description (e.g. a torrent is said to contain a video, but it contains only a
snapshot
Snapshot, snapshots or snap shot may refer to:
* Snapshot (photography), a photograph taken without preparation
Computing
* Snapshot (computer storage), the state of a system at a particular point in time
* Snapshot (file format) or SNP, a file ...
of a moment in the video, or in some cases
malware
Malware (a portmanteau for ''malicious software'') is any software intentionally designed to cause disruption to a computer, server, client, or computer network, leak private information, gain unauthorized access to information or systems, depri ...
).
Freeleech
:Freeleech means that the download size of the torrent does not count towards your overall ratio, only the uploaded amount on the torrent counts toward your ratio.
Grab
:A torrent is grabbed when its metadata files have been downloaded.
Hash
:The
hash
Hash, hashes, hash mark, or hashing may refer to:
Substances
* Hash (food), a coarse mixture of ingredients
* Hash, a nickname for hashish, a cannabis product
Hash mark
*Hash mark (sports), a marking on hockey rinks and gridiron football field ...
is a digital fingerprint in the form of a string of
alphanumeric
Alphanumericals or alphanumeric characters are a combination of alphabetical and numerical characters. More specifically, they are the collection of Latin letters and Arabic digits. An alphanumeric code is an identifier made of alphanumeric ch ...
characters (typically
hexadecimal
In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, hexa ...
) in the .torrent file that the client uses to verify the data that is being transferred. "Hash" is the shorter form of the word "
hashsum
A hash function is any function that can be used to map data of arbitrary size to fixed-size values. The values returned by a hash function are called ''hash values'', ''hash codes'', ''digests'', or simply ''hashes''. The values are usually ...
".
:Torrent files contain information like the file list, sizes, pieces, etc. Every piece received is first checked against the hash. If it fails verification, the data is discarded and requested again.
:Hash checks greatly reduce the chance that invalid data is incorrectly identified as valid by the BitTorrent client, but it is still possible for invalid data to have the same hash value as the valid data and be treated as such. This is known as a
hash collision
In computer science, a hash collision or hash clash is when two pieces of data in a hash table share the same hash value. The hash value in this case is derived from a hash function which takes a data input and returns a fixed length of bits.
Al ...
. Torrent and p2p files typically use 160 bit hashes that are reasonably free from hash collision problems, so the probability of bad data being received and passed on is extraordinarily small.
Health
:Health is shown in a bar or in % usually next to the torrent's name and size, on the site where the
.torrent
file is hosted. It shows if all pieces of the torrent are available to download (i.e. 50% means that only half of the torrent is available). Health does not indicate whether the torrent is free of viruses.
Hit-and-run
:To intentionally "leech" a file; downloading a file while seeding as little as possible. It's abbreviated HnR or H&R.
Index
:
:An index is a list of .torrent files (usually including descriptions and other information) managed by a
website
A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google Search, Google, Facebook, Amaz ...
and available for searches. An ''index'' website can also be a ''tracker''.
Interested
:Describes a downloader who wishes to obtain pieces of a file the client has. For example, the uploading client would flag a downloading client as 'interested' if that client did not possess a piece that it did, and wished to obtain it.
Leech
:
:''Leech'' has two meanings. Often, ''leecher'' is synonymous with ''downloader'' (see above): simply describing a ''peer'' or any client that does not have 100% of the data.
:The term ''leech'' also refers to a ''peer'' (or peers) that has a negative effect on the swarm by having a very poor share ratio, downloading much more than they upload. Leeches may be on asymmetric Internet connections or do not leave their
BitTorrent client
The following is a general comparison of BitTorrent clients, which are computer programs designed for peer-to-peer file sharing using the BitTorrent protocol.
The BitTorrent protocol coordinates segmented file transfer among peers connected i ...
open to seed the file after their download has completed. However, some leechers intentionally avoid uploading by using modified clients or excessively limiting their upload speed.
Lurker
:
:A ''lurker'' is a user that only downloads files from the group but does not add new content. It does not necessarily mean that the lurker will not seed. Not to be confused with a ''leecher''.
Magnet link
:A mechanism different from a
.torrent
metafile which can be used to identify a set of files for BitTorrent based on content, as opposed to referencing any particular tracker. The method is not limited to BitTorrent data. See
Magnet URI scheme
Magnet is a Uniform Resource Identifier, URI scheme that defines the format of magnet links, a de facto standard for identifying files (Uniform Resource Name, URN) by their content, via Cryptographic hash function, cryptographic hash value rathe ...
.
Overseeded
:In private trackers using ratio credit, a torrent is ''overseeded'' when its availability is so high that seeders have difficulty finding downloaders.
p2p
:
:In a p2p network, each node (or computer on the network) acts as both a client and a server. In other words, each computer is capable of both responding to requests for data and requesting data itself.
Peer
:A ''peer'' is one instance of a BitTorrent client running on a computer on the
Internet
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...
to which other clients connect and transfer data. Depending on context, "peer" can refer either to any client in the swarm or more specifically to a downloader, a client that has only parts of the file.
Piece
:This refers to the torrented files being divided up into equal specific sized pieces (''e.g.'', 64kB, 128kB, 512kB, 1MB, 2MB, 4MB or 8MB). The pieces are distributed in a
random
In common usage, randomness is the apparent or actual lack of pattern or predictability in events. A random sequence of events, symbols or steps often has no :wikt:order, order and does not follow an intelligible pattern or combination. Ind ...
fashion among peers in order to optimize trading efficiency.
Ratio credit
:A ''ratio credit'', also known as ''upload credit'' or ''ratio economy'', is a currency system used on a number of private trackers to provide an incentive for higher upload/download ratios among member file-sharers. In such a system, those users with greater amounts of bandwidth, hard drive space (particularly
seedbox
A seedbox is a high-bandwidth remote server for uploading and downloading of digital files from a P2P network. The bandwidth ranges generally from 100 Mbit/s to 20 Gbit/s. After the seedbox has acquired the files, people with access to the see ...
es) or idle computer
uptime
Uptime is a measure of system reliability, expressed as the percentage of time a machine, typically a computer, has been working and available. Uptime is the opposite of downtime.
It is often used as a measure of computer operating system reliabi ...
are at a greater advantage to accumulate ratio credits versus those lacking in any one or more of the same resources.
Scraping
:
:This is when a client sends a request to the tracking server for information about the statistics of the torrent, such as with whom to share the file and how well those other users are sharing.
Seed / seeding
:A ''seed'' refers to a machine possessing all of the data (100% completion). A ''peer'' or ''downloader'' becomes a seed when it completely downloads all the data and continues/starts uploading data for other peers to download from. This includes any ''peer'' possessing 100% of the data or a
web seed. When a ''downloader'' starts uploading content, the peer becomes a ''seed''.
:''
Seeding
The term seeding and related terms such as seeded are used in several different contexts:
*Sowing, planting seeds in a place or on an object
*Cloud seeding, manipulating cloud formations
*Seeding (computing), a concept in computing and peer-to-pee ...
'' refers to leaving a peer's BitTorrent client open and available for additional individuals to download from. Normally, a peer should seed more data than download. However, whether to seed or not, or how much to seed, depends on the availability of downloaders and the choice of the peer at the seeding end.
Share ratio
:A user's share ratio for any individual torrent is a number determined by dividing the amount of data that user has uploaded by the amount of data they have downloaded. Final share ratios over 1.0 carry a positive connotation in the BitTorrent community, because they indicate that the user has sent more data to other users than they received. Likewise, share ratios under 1 have negative connotation.
Snatch
:A torrent is snatched when its data files have been downloaded.
Snubbing
:An uploading client is displayed as ''snubbed'' if the downloading client has not received any data from it in over 60 seconds.
Super-seeding
:When a file is new, much time can be wasted because the
seeding
The term seeding and related terms such as seeded are used in several different contexts:
*Sowing, planting seeds in a place or on an object
*Cloud seeding, manipulating cloud formations
*Seeding (computing), a concept in computing and peer-to-pee ...
client might send the same file piece to many different peers, while other pieces have not yet been downloaded at all. Some clients, like
Vuze
Vuze (previously Azureus) is a BitTorrent client used to transfer files via the BitTorrent protocol. Vuze is written in Java, and uses the Azureus Engine. In addition to downloading data linked to .torrent files, Azureus allows users to view, p ...
,
μTorrent
μTorrent, or uTorrent (see pronunciation) is a proprietary adware BitTorrent client owned and developed by Rainberry, Inc. with over 150 million users. It is the most widely used BitTorrent client outside China; globally only behind Xunlei. Th ...
, and
qBittorrent
qBittorrent is a cross-platform free and open-source BitTorrent client written in native application, native C++. It relies on Boost (C++ libraries), Boost, Qt (software), Qt 6 toolkit and the libtorrent-rasterbar library (for the torrent back-e ...
have a "
super-seed" mode, where they try to only send out pieces that have never been sent out before, theoretically making the initial propagation of the file much faster. However the super-seeding becomes less effective and may even reduce performance compared to the normal "rarest first" model in cases where some peers have poor or limited connectivity. This mode is generally used only for a new torrent, or one which must be re-seeded because no other seeds are available.
Swarm
:Together, all ''peers'' (including ''seeds'') sharing a ''torrent'' are called a ''swarm''.
For example, six ordinary ''peers'' and two ''seeds'' make a ''swarm'' of eight. This is a from the predecessor to BitTorrent, a program called Swarmcast, originally from OpenCola.
:BitTorrent may sometimes display a swarm number that has no relation to the number of seeds and peers you are connected to or who are available. E.g. it may show 5 out of 10 connected peers, 20 out of 100 connected seeds, and a swarm of 3.
Torrent
:A ''
torrent
Torrent or torrents may refer to:
* A fast flowing stream
Animals
* Torrent duck, a species of the family Anatidae
* Torrent fish
* Torrent frog, various unrelated frogs
* Torrent robin, a bird species
* Torrent salamander, a family of sala ...
'' can mean either a .torrent
metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including:
* Descriptive metadata – the descriptive ...
file or all files described by it, depending on context. The ''torrent file'' contains metadata about all the files it makes downloadable, including their names and sizes and
checksum
A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify data ...
s of all pieces in the ''torrent''. It also contains the address of a ''tracker'' that coordinates communication between the peers in the swarm.
Tracker
:
:A ''tracker'' is a server that keeps track of which seeds and peers are in the swarm.
Clients report information to the tracker periodically and in exchange, receive information about other clients to which they can connect. The tracker is not directly involved in the data transfer and does not have a copy of the file. It only receives information from the client.
References
{{BitTorrent
BitTorrent
BitTorrent terms
Wikipedia glossaries using subheadings
ru:BitTorrent#Терминология