TOR
Tor, known as "The Onion Router", is an anonymization service. Tor makes it difficult to trace your online activities back to you and protects your privacy online. It basically works by routing your Internet traffic through their Tor network made of randomly selected relays which are actually run by volunteers from all around the world.
All the Internet traffic passing though the relays gets encrypted and re-encrypted multiple times until it gets to the exit node.
At the exit node, the last layer of encryption gets decrypted and the data is sent to the destination without exposing the sender's is.