A torrent is a file type used by BitTorrent file-sharing protocol. It authorizes and points to a remote server that contains the location of different remote hosts with an instance or part of the file to be shared or downloaded.
A torrent file is a metadata file type that primarily stores the URLs of host servers that manage the communication, data transferring and other protocol-specific administration in the file-sharing and downloading process.
Techopedia explains Torrent
The torrent file type is an integral component of the BitTorrent file sharing mechanism, which relies on this file to effectively ensure error-free downloading. A torrent file is created by a central BitTorrent-enabled host server, which embeds the URL of different trackers that serve as the bridge between the host on which the file needs to be downloaded and the remote peers seeding the pieces of the original file.
Besides a tracker URL, a torrent file may also contain information such as the name of the file, its author or creator, its size, the pieces of the file and their size and location.