I have been an iPhone user for the past three years. When I picked Apple's iPhone 4S last month, I knew the untethered iPhone jailbreak was not out yet. I wanted to jailbreak my device and I really wanted to explore Cydia apps on my iPhone 4S.
Many smartphone, tablet, and game console makers include a layer of Digital Rights Management (DRM) software on their products. This DRM exists either to limit the software you can run on it, or is there for security reasons. Jailbreaking is the process of hacking these devices to bypass DRM restrictions, allowing you to run "unauthorized" software and to make other tweaks to your operating system.
More technically, tethered or untethered jailbreaking can be thought of as the process of installing "a modified set of kernel patches (the kernel being the supervisor of the operating system) that allow you to run unsigned code," as saurik explains. It also gives you root-level access, which is otherwise unavailable. The term "root" comes from UNIX, where it is the superuser account that has unrestricted rights and permissions to all files. This provides you with added flexibility, but it also has some inherent dangers (more on that later).
You can alter or install anything onto your phone or tablet such as UI hacks (like the 5-icon dock) or unofficial apps (like classic console emulators) that would not otherwise be accepted into the App Store. Saurik's alternative app store, called Cydia, is arguably the definitive repository of such apps or tweaks. Cydia is so ubiquitous in iOS jailbreaking circles that most jailbreak tools install it automatically.
iPhone hackers first coined the term "jailbreaking" in reference to breaking the iPhone out of Apple’s iTunes “jail.” The term has since been (somewhat erroneously) used in a more general sense to refer to similar hacks made to other platforms like Android, where it's also known as “rooting”. In any case, the basic concept is the same, regardless of what you call it.
The brilliant untethered iPhone jailbreak Dev Team finally launched Absinthe, just a day after my iPhone 4S purchase. Absinthe, as most of you may already know, is a free jailbreaking tool -- untethered -- downloaded almost a million times.
It is an untethered jailbreak, which means you don't have to plug your iPhone 4S to the computer every time you want to reboot your phone.
Steps to jailbreak untethered is easy:
Step 1: Download Absinthe -- freely available for Windows, Mac, Linux.
Step 2: Launch Absinthe, connect your iPhone 4S to the PC.
Step 3: Hit the "Jailbreak" button. Wait for 5 minutes and your iPhone 4S will be successfully jailbroken.
This easy-to-achieve jailbreak doesn't require you to take any other action. You can now install Cydia tweaks, customize iPhone themes and add Siri tweaks.