aes Encryption questions

[Bob Sneidar]

All the talk about encryption recently got me onto updating my encryption library. I noticed that I can encrypt the same string using the same depth (aes128 for example) and same key, and each time I get a different result. But decryption always works. That blows my mind. Secondly I noticed that using a salt value when encryption does not require the salt value when decrypting. It works either way. If that is the case, why even use a salt??

Bob S