How is an HMAC different than a hash?

Related questions

1. How does an HMAC work?
2. Is sha1 secure?
3. What is the most secure hashing algorithm?
4. What is required by the Advanced Encryption Standard?
5. How does Hmac provide authentication?
6. How good is AES 256 encryption?
7. What is SHA HMAC?
8. How does a message authentication code work?
9. Is sha512 better than sha256?
10. What are the message authentication functions?

Tags

1. #considered
2. #totally
3. #beast
4. #function
5. #which
6. #functions
7. #however
8. #integrity
9. #different
10. #message
11. #verifying
12. #secret
13. #keyed
14. #authentication
15. #salts
16. #happens
17. #meant
18. #built