Everyone likes being in control, which is why gaining root access - aka rooting your Android device - is so alluring. Just like jailbreaking an iPhone or iPad, rooting with Android uses various tools to hack Android, giving you full control over the root folder, which is administrator-level access.
At this point you can then do pretty much anything you like to the poor device, including replacing the entire OS with a custom built one. Less dramatically but equally as useful, it enables full system backups, along with a host of advanced apps and geeky system tools sporting new features.
There are dangers and issues with rooting. It usually voids the warranty, but re-flashing a stock ROM and locking the bootloader again can revert a device back to an official state.
The big danger is that if instructions aren't followed correctly, this can result in a dead device known as 'bricked', because at this point, it's no better than a brick! If this happens, your void warranty is going to be a major issue.
As scary as all of that is, bricking is a relatively uncommon thing. As long as you have a working bootloader you're always able to recover the device. It's when you break the bootloader that things really go wrong.
Unlike Apple-based Jailbreaking, where only a small number of devices are involved, rooting an Android device is more versatile. Effectively every device requires its own techniques, tools and tricks.
Thankfully, many of these can be reused from device to device, and as new ones appear, industrious hackers are quick to modify existing tools to the job. These can start out as rather rough and ready command line programs which, over time, are polished into slicker all-in-one root and flashing tools.
Both of these sites offer dedicated forums for each specific model of phone. You'll find that for less popular models, much of the talk is if and when an updated ROM release is going to appear, but guides and tools for rooting and replacing the bootloader will be available.
No matter what your device, you'll need to take your time, read and research the posts. You'll find many are complex, requiring you to install obscure drivers, use the command line with complex switches and perform multiple boots of your device using its recovery mode.
If you find a post that seems to offer suitable advice, we'd recommend reading ahead in the thread to see what experience other people have had with it. Doing so can highlight a bogus ROM or at least problems that others have run into and how to avoid them.
Be backed up
A key advantage of an unlocked and rooted device is that it enables full backups. If you're experimenting for the first time, having a full backup of your carefully tailored phone installation can be a godsend - especially when you discover that the temping custom Jelly Bean ROM is full of bugs - as it makes restoring your phone a breeze.
There are two approaches here. One is to use an Android-based app with root access. One of the most widely suggested is Titanium Backup Root. The other we'd recommend is MyBackup Root. Both enable complete backup and restore of all your apps, settings and data.
The other approach is to use a custom recovery tool such as ClockworkMod Recovery. This is a replacement for the standard Recovery Mode that's usually accessed by pressing the power and volume down button after the device is powered off.
You'll likely end up installing this or a similar tool, as it makes updating and installing custom ROMs far easier, alongside it supporting built-in low-level backup and restore tools.
A simpler reason to root your device rather than a full ROM replacement is that a root offers enhanced features for a wide range of apps. As we've seen, backup tools can do a better job, offering lower-level access to app data.
There are plenty of other notable mentions, such as Cerberus anti theft. One of the more popular remote tracking and wiping apps, with a rooted device it can hide itself far better, making it almost impossible to discover.
Overclocking becomes possible on rooted devices. Choose from any of the overclocking tools on the Play Store and tweak out more speed or battery life, take No-frills CPIU Control as an example.
A host of other tools gain additional features. Take most file explorers - they'll gain complete access to areas of Android that were otherwise hidden.
One of the most common reasons to root is to get your hands on upgraded ROMs also known as the firmware, which - more simply put - are better and newer versions of Android for your phone or tablet.
While you languish on Gingerbread, there are fancy-dan hackers out there running around with Jelly Bean on their phones. Android effectively has to be built specifically for every device made, so you can't just install it.
Drivers and settings are needed for each component within the device, and despite Android's open-source nature, these components can remain closed source for some time. When it comes to custom ROMs, this means you get a mixture of quality and types.
Some can be built from officially released code, others are hacked together, often with the wireless, mobile radio, GPS, camera, audio or other components not working.
While these can be individual efforts, a number of long-standing ROMs exist for a wide number of devices. The best known are CyanogenMod, Paranoid Android, MIUI Android and Android Open Kang Project. CyanogenMod is the best known and offers a close-to stock experience but with a host of advanced features under the surface.
If you find your device is supported by one of these groups then you know you're on to a good thing. Outside of these groups you'll have plucky forum groups or individuals attempting to cobble together their own custom ROMs.
At this point, the quality and effectiveness of the ROM is going to vary widely. But if you're hacking your Android, that's all part of the fun!