During the 1930s, polish scientists reproduced a german device called enigma. just before the beginning of wwii, they sent this machine to britain. why was possession of this machine an advantage to the allies?

In obtaining this device, the British could intercept german messages and decrypt them. fun fact, alan turing created the first computer that was able to decrpyt the Nazi German Enigma, if it weren't for him, the allies wouldn't have won the war.