Tethered vs Untethered Jailbreak
The process of jailbreaking has been a necessity for people who find Apple’s practices to restrictive. It provides root access to your iOS device (i.e. iPhone, iPod, iPad) so that you can install apps or themes that you cannot find on the AppStore. There are two types of jailbreaks, the tethered and untethered; this has absolutely nothing to do with tethering for an internet connection. The main difference between a tethered and untethered jailbreak is that you need to have a computer to boot the iOS device in a tethered jailbreak but not in an untethered jailbreak.
In an untethered jailbreak, you basically have a permanently jailbroken iOS device. You can turn it off or reboot it without any problem at all. In a tethered jailbreak, you cannot just turn your iOS device on like normal. You need to use the program you used for the jailbreak to boot the iOS device while it is connected to the computer via its cable. There is absolutely no difference between the two when it comes to functionality but just be watchful of your battery meter and keep it at full, or close to it, at all times. A tethered jailbreak is not advisable if you routinely travel or use your iOS device quite heavily.
If there is no difference in the functionality of the two, why do some people choose a tethered jailbreak over an untethered jailbreak? The answer to that is really very simple. Every time Apple releases a new update, hackers attempt to jailbreak it. Apparently, it is easier to create a tethered jailbreak compared to an untethered jailbreak. Because of this, tethered jailbreaks are released way ahead of untethered jailbreaks.
If you are satisfied with your jailbroken iPhone or iPad, there is really no pressing reason to get the next update with an untethered jailbreak. You can just wait it out until a new untethered jailbreak for that update is available. If you really can’t wait and need the latest update there is no problem with a tethered jailbreak as long as you are never too far away from a computer to boot your device if shuts down. But as long as you keep your iOS device charged at all times, you would not need a computer.
Summary:
A tethered jailbreak requires a computer to boot your device while an untethered jailbreak doesn’t
Tethered jailbreaks appear much sooner than untethered jailbreaks