What is the Difference between a Hash and MAC (Message Authentication code)?

Question

What is the Difference between a Hash and MAC (Message Authentication code)?

By their definitions they seem to serve the same function.

Can someone explain w

Answer 1

HASH FUNCTION: A function that maps a message of any length into a fixed length hash value, which serves as the authenticator.

MAC: A function of the message and a secret key that produces a fixed length value that serves as the authenticator.