What Does Tethered and Untethered iPhone Jailbreak Mean?

There are two popular terms can be founds on the Apple devices (iPhone, iPod or iPad) unofficial hack, namely Tethered and Untethered Jailbreak. People who already familiar with iPhone/iPod Jailbreak processes will not confused with the terms. But there are many peoples not yet certainly know what are the meaning of Tethered and Untethered Jailbreak.

First, what does tethered jailbreak mean?

Tethered jailbreak means a temporary jailbreak. You must hooked up your iPhone/Apple iDevice onto laptop or computer and run appropriate desktop application for Jailbreak (Blackra1n, Redsn0w or iTunes) to maintain the Jailbroken state when turn your iPhone back on. You must do this each time your iPhone restart. If not so, you'll loose your jailbroken iPhone/iDevice or the device will just stay in Recovery Mode (ie. in iPod).

Jailbroken iPhone Home Screen: WinterBoard

For Example, if you have installed MobileSubstrate tweaks that hook into iPhone SpringBoard (as WinterBoard) or other important OS routines, your iPhone boot will actually fail. You’ll just get stuck with the Apple logo. Use Redsn0w desktop application to have the option Just boot tethered right now.

You have to install Cydia each time you reboot the iPhone. All Cydia applications, like UltraSn0w, that used in device unlocking also have to be installed again.

Then, what does untethered jailbreak mean?

The Untethered Jailbreak is a contrary than before. It's what you actually think of iPhone/iPod hack. Untethered Jailbreak is a permanent Jailbreak and means rebooting the device won’t loose the jailbreak. User don’t have to install Cydia every time reboot. It's also not needed to hooked iPhone/iPod up to desktop computer on each reboot.

But keep in mind that permanent (untethered) jailbreak will be lost if you do an iOS upgrade.

Successful Jailbreak: Apple iPhone Boot Screen

Untethered Jailbreak not always be able to executed. iPhone Dev-Team is not always be immediately able to find ways to do the jailbreak permanently. If you want to do the jailbreak, then the options that can be taken is tethered jailbreak. When untethered jailbreak is then possible, you can take this later.