What is the difference between 'unlocked' and 'jailbroken' when referring to a mobile phone?

'Unlocked' vs 'Jailbroken'"Unlocked" simply means that the phone is able to use any SIM card from any network. For example, if you bought an iphone bundled with AT&T, unlocking it will let you put in a SIM card from any other network.

"Jailbroken" means you are not limited to Apple's standard OS. By jailbreaking an iPod you will be able to access many more features such as adding an Android lock to your phone or displaying custom application icons. However, jailbreaking voids your warranty and you risk bricking your iPod when you jailbreak it.