What is "rooting"?
Rooting is the process of gaining root access on your device.
Rooting a phone allows a user a higher access level akin to Administrator on a Windows PC. It allows for greater access to certain core system functions that a normal end-user wouldn't use or need to use.
Most devices running Android need to be rooted for installing custom versions of the Android system known as ROMs. This is because in the stock configuration (unrooted), user-installed applications do not have write access to core parts of the file system and, thus, are not able to replace or modify the operating system itself.
Rooting is also necessary for certain applications and widgets that require additional system and hardware rights such as for rebooting the phone, certain backup utilities, and hacks for hardware LEDs. Rooting is also needed to disable or remove applications such as City ID preinstalled by vendors like Verizon Wireless. Rooting the phone typically also includes installing an application that supervises what applications are granted root rights.
It must be noted that rooting a device usually voids the warranty offered by the manufacturer.
OK, ok, that's all nice -- but how can I root my device?
First, check our rooting index if your device is already listed. If so, follow the link to that question, which in most cases will contain instructions on how to perform the necessary tasks. If the question does not contain any answer, do not open a new question (that would immediately be closed as duplicate). Also, do not place a "me too" answer (would also be removed). If you want to push things, and you already have enough reputation, consider placing a bounty instead. Upvote the question to bring it "further to the top" of highly-voted ones also might gain some attention.
If your device is not listed in the index: To make sure a corresponding question was just "missed", search for "[rooting] Samsung Plastic Phantastic" (OK, replace the "Samsung Plastic Phantastic" with the name of your device). If you find a corresponding question, add it to the index and continue as described above.
Still not found? OK, then go on: create a new question, and link it to the index. Now wait for answers. If you don't get an answer withing 2 days, your question becomes eligible for placing a bounty -- so you again can continue as described above.
Starting Jan 2012 we are going to allow one "How to root?" question per device. Just search for [rooting] and your device or refer to the index in How do I root my Android device?. If the question doesn't exist yet, create one and add it to this index.
- root: questions specifically requiring root permissions (not including "rooting" itself)
- unrooting: Getting rid again of your "root account" (e.g. to turn in your device under warranty)
- z4root: a rooting method
Further readings on this site
- What does “to root a phone” mean?
- Are there any risks to rooting a device?
- What are the security disadvantages of rooting an Android phone?
- How do I perform a full pre-rooting backup of an Android phone?
- How do I root my Android device?
- How does rooting work?
- I've rooted my phone. Now what? What do I gain from rooting?
- Are there any tools to sandbox a malware application even more than the granted permissions on Android?
- Security implications of rooting your android phone (Security.SE)
- How to root any Android device running ICS or Jelly Bean (AndroidAuthority; for 4.0 & 4.1)