also, it is exactly the same as the nonce, i've always hated that ambiguity. salt=nonce

you can use different encryption schemes, CBC, CTR, etc, but they all use a cleartext nonce in front, and the olden days they called that a "salt" - it's like a HD derivation path, same prinicple, ensures the hash you generate is different, no matter which way it's sliced by the encryption algo