A .torrent file is a metadata file used by the BitTorrent peer-to-peer file sharing protocol. It doesn't contain the actual data being shared, but rather information about the files and folders to be distributed, including their names, sizes, and checksums (hash values) for verification. It also contains the URL of a tracker, which is a server that helps peers find each other to exchange data. When you open a .torrent file with a BitTorrent client, the client reads this metadata and uses it to connect to the tracker and other peers who are sharing the desired files. The client then downloads the files in small pieces from multiple sources simultaneously, reassembles them, and verifies their integrity using the checksums provided in the .torrent file. This distributed approach allows for faster and more resilient file sharing compared to traditional methods.