What is Android Rooting?

Rooting in Android is the same as jailbreaking in OS. It allows Android users to access subsystem of your device and work with it in the same way as with SD Card or internal storage.
Root user (Superuser) has unlimited access to any file or folder and can perform any operation in Android OS.
To put it simple, root access is a possibility to work with Android root filesystem without any restrictions.

What happens when you root your phone?
Rooting a phone is modifying its filesystem in order to give Superuser privileges in the root directory of a smartphone or tablet.
A root app gains complete access to Android. As a result, root user acquires an unlimited range of permissions on an Android device. If the app also is given Superuser access, it can perform absolutely any operation on the phone.

How to find out if your phone is rooted?
In fact, it’s pretty easy to find out whether your phone is rooted or not. If it’s new and using basic Android firmware, I figure you don’t have root access.
If your phone had been used before you got it or you can’t remember if you rooted it, check the status with the help of Root Checker tool. It will identify if your Android device has Superuser / su access.

Why to root Android: main reasons
Rooting a mobile device enables you to bypass any default restrictions of a smartphone. In particular, what can you do with a rooted phone:
run more applications with a wide spectrum of privileges and manually accept or refuse permission to a certain application installed on Android;
install an unofficial firmware without any obstacles on Android OS side;

Does rooting damage your phone?
Manufacturers of Android-powered mobile devices don’t encourage rooting. Unskilled handling of Superuser permissions can cause smartphones and tablets breakdown.
We can single out three main dangers of enabling root access:

1. Getting out of warranty. Some carriers refuse a warranty repair when they find out that your phone was rooted.

Yet keep in mind that you can disable root access to the filesystem of a mobile device any time. If you need to give your device to repair, simply roll back to factory firmware, and no one is going to find out that your device was rooted.

2. Your phone turning into a “brick”. In case rooting goes wrong, your phone risks turning into a so-called “brick”.

A safe way of avoiding phone breakdown is following the instructions from reliable web resources. Make sure that the algorithm is applicable to your device and custom firmware is compatible with it.

Examine reviews by the users of the same device as yours: they may have already either rooted it or turned into a “brick” and are being weirded out.

3. Increased security vulnerability. Gaining root access on Android also undermines security. Services and applications with unrestricted root permissions can make the system prone to malware, that’s why Google refuses technical support of its services (for instance, Google Wallet) to rooted devices.