What Is a Torrent "Meta File"?

The BitTorrent protocol is a widely used system for file sharing. File sharing is the practice of copying a file from another private individual over the Internet. BitTorrent has its own unique procedures and creates its own terminology. A torrent is a file available for copying. A torrent file, or torrent meta file, is a small file that kicks off the file sharing process for a torrent.

Meta data is data about data. That is, the torrent meta file does not contain any of the contents the user wants to copy, but describes the file that searcher needs and links to a system detailing how to find it. The program contains few lines. It names the file or folder available for download. Each torrent is divided into segments, and the torrent meta file gives the size of these segments. The creator of the meta file has to nominate a "tracker" and list its address in the torrent program. A tracker is a location where the owners of a copy of a file register their addresses. Anyone wishing to download the file will contact these sources for segments of the file.

The torrent meta file is written in plain text. Each heading is followed by a colon and then by values. The file, however, is not readable by humans. On completion of the file-writing process, it is encoded. The system used to encode the torrent file is called bencoding. This is sometimes written as "BEncoding" and is pronounce "bee encoding." Bencode wraps text in codes representing the value's data type.

BitTorrent was invented in 2001 and is a file-sharing system using peer-to-peer architecture. Peer-to-peer does not use a central server to control access, and so it is free for everyone to use. The only server element of a BitTorrent download is the tracker reference site. Each downloader can copy different segments of the same file from different sources simultaneously. This reduces the burden on any holder of the file and speeds up the download process.

The torrent meta file can only be opened by a torrent client. The client is like a browser listing the torrents the user is currently uploading or downloading or both. On opening the torrent program, the client presents the user with a list of the files the program defines. The user has the option to deselect some of the files before proceeding. Once this stage is completed, the client contacts the tracker and gets a list of addresses where sources for the file are held. The client program then requests segments of the file from one or more of these sources.