Untethered jailbreak

An untethered jailbreak is a jailbreak where your device does not require you to reboot with a connection to an external device capable of executing commands on the device. Currently, all iPhones and iPod touch models are jailbreakable in this method and, with the exception of the most recent iPhone 3GS and iPod touch 3G, the current released devices will always be subject to pwnage. The only exception is Linux on your device, where it is still in a tethered form.