Root is a term that means a couple of things. It indicates the user has complete control of the device and software on the device, an administrator level account. It means the first level of the directory tree, which is not visible to a normal user. It means the built in safeguards of the system are bypassed and nefarious software can tamper with your device without your knowledge. To root your device means that you have complete control of it. This voids the warranty from the manufacturer and support from your wireless provider as well should you have any problems. Rooting lets you install and use software that normally would not run or install on your device. This can open up new or improved software options. However, mistakes with such software can destroy your device or "brick" or "soft brick" it. Brick being your device is no more useful as a phone or hand held computer than a brick. A soft brick can usually be tweaked to operate again if you're a knowledgeable user. Sometimes the rooting process itself goes wrong and can brick your phone. Reasons rooting is good Firewall controls-- privacy and protection reasons adblocking--speed, infection, privacy, though it's not always pretty as pages may not display properly or some parts of games can be weird sometimes. Privacy tools-- fine tune app permissions, Automation--you have more options for automating the behaviors and use of the phone. You can still automate a regular phone a fair amount, but there are more limits. Security Overclocking/underclocking including custom kernels. Make your device faster, or more battery efficient--aggressive overclocking can fry your phone, or custom kernels can softbrick. Or badly sourced software of such nature can be malware. You can remove bloatware. Reasons rooting is bad You're on your own for support. No warranty, no in-store help. Higher risk of malware for less skilled users Buggy rooted phones and software can be more unstable depending on the user and what they do. You're more likely to run into unintended uses of the phone such that the software was never tested or debugged for such uses. No more updates Each software update to the OS will break your root. You can usually wait for the hard core techies to figure out how to root the new update, then re-root at that time with the updated features. Root is not for everyone. Some carriers are more hostile than others. Verizon and AT&T phones are usually more locked down than T-Mobile for example. You need to research how to root your phone, and this includes the carrier and software version you're using.