What is the difference between a digital signature and a hash?

A digital signature is used to authenticate the identity of the sender of a digital document or message. It is a cryptographic signature that uses a form of public key cryptology. A hash, on the other hand, is a one-way mathematical algorithm used to transform data into a fixed-length string of characters known as a hash value. It is used to validate data integrity, detect data tampering, or to produce unique identifiers.