A large file is divided into numerous small segments called pieces .
Pieces are downloaded in a seemingly random order based on which peers have them and which are fastest to provide them.
The process relies on a distributed network rather than a central server:
Each piece has a unique cryptographic hash (SHA-1) in the torrent file, allowing the client to verify every segment for integrity as it arrives. Benefits of Fragmented Downloading
Clients often use a "rarest-first" strategy, prioritizing pieces that are least available in the "swarm" (the group of peers sharing the file) to ensure overall file health.