A torrent file is a small file that contains metadata about files and folders to be shared over the internet using the BitTorrent protocol. It does not contain the actual content but instead includes information such as the file names, sizes, and the locations of the pieces of the files on various computers. This allows users to download and share large files efficiently. When a user opens a torrent file with a BitTorrent client, the client connects to other users (peers) who have the same file. The client then downloads pieces of the file from multiple sources simultaneously, making the process faster and more reliable. This method is commonly used for sharing media files, software, and other large data sets.