Before you actually jailbreak, it is better to know about the difference between a tethered and an untethered jailbreak. As a newbie who used Evasi0n (or Absinthe in the past), you mostly won’t realize that these tools are mankind’s greatest ones that let complete freedom become a possibility on the iPhone.
Jailbreaking your iPhone has become / been made easy by blokes like @pod2g, @i0nic, @MuscleNerd etc. What was once a humongous 72-step process (early 2008) has now turned into a few-clicks kind of an event. All you do is connect your iPhone, run the software and bam! Your iPhone is successfully jailbroken.
But the work behind is enormous and many times nerve-wracking.
Jailbreaking can be of two flavors: tethered and untethered. Everyone of you who has used Absinthe or Evasi0n to jailbreak your iPhone/iPad/iPod Touch is now using an untethered jailbreak. So what exactly are these terminologies? First, the background.
Jailbreaking actually modifies the root of your iDevice. This helps apps and tweaks from Cydia to be installed on your iOS device which would normally not be allowed.
The way your jailbreak setup works when you reboot your iPhone is the criteria that decides whether your jailbreak is a tethered one or an untethered one.
1). Tethered Jailbreak
A tethered jailbreak is mostly the first type of jailbreak that arrives on the web whenever a new iOS is released. The tethered jailbreak has all the characteristic features of an untethered jailbreak but the only difference is, you can’t reboot your iOS device without connecting it to the computer and using a specific tethering software (like Redsn0w).
For obvious reasons, if you have a tethered jailbreak on your iPhone, you’ll think twice before trying to reboot your gadget. It’s not as cumbersome as it sounds but anything that has more than one step will, in comparison to the usual reboot process, be complicated.
2). Untethered Jailbreak
After the devs create the tethered jailbreak and test it out, it’s time to patch things up and figure out a way to create the untethered. And it simply means: you can reboot your iPhone just as normally as you would, without having to connect it to your computer or run Redsn0w’s Just Boot.
People prefer untethered – and some even wait for it till they jailbreak their iPhones – because it’s complete. Having to use a computer and Redsn0w just to reboot often sucks because what if your iPhone got turned off (low battery, may be?) when you are away from any access to a computer?
So that’s about all the difference there is between a tethered and untethered jailbreak.