The Enigma was a cipher machine used by the German military during World War II to encode secret messages. It employed a series of rotating disks to create complex substitutions, making it difficult for enemies to decipher the communications. The machine's design allowed for a vast number of possible settings, enhancing its security. The breaking of the Enigma code was a significant achievement for the Allies, particularly by the team at Bletchley Park led by mathematician Alan Turing. Their efforts in deciphering the Enigma messages provided crucial intelligence that contributed to the Allied victory in the war.