Root, JailBreak and Legality

You may encounter many such jargons used by many who are in favor of up-to-date technology about "Gadget" (A gadget is a small technological object such as a device or an appliance that has a particular function typical examples are smart phone, tablet). 

Root: 

    Rooting enables users to use the superuser, or root, permissions of the Linux-based operating system (OS)(Android is based on Linux system) thus have more control over it,thus overcome limitations carriers or manufacturers put on your devices. One example is Amazon Kindle Fire, the Android on the Fire is extensively customized to allow users more easily buy stuffs from them, and has many limitations. Another example is the fire-saled HP TouchPad (TP), the WebOS does not have as many apps as on Android, thus a totally new Android has to be installed on the TP.

    Advantages of rooting are: more freedom to control your gadgets, fun to explore

    Disadvantages are: risk of "bricking" (Firmware cannot start and run on your device) your gadgets and loss your data; void your phone’s factory and/or service provider warranty  

JailBreak:         

   This is often applied to only Apple's system IOS. Hacking the iPhone, iPod touch and iPad allows users to
gain full control of the entire operating system (IOS) or Unix filesystem (changing the root of the directory to the root directory tree "/").

Advantages-Being able to add additional apps to your Apple gadgets and allows Apple fans to customize icons, keyboards...etc.

Legality:
   We do not need to worry about getting into trouble for rooting.
On July 26, 2010, the U.S. Copyright office announced a new exemption making it officially legal to root a device and run unauthorized third-party applications, as well as the ability to unlock any cell phone for use on multiple carriers. (WiKi; U.S. Copyright Office). Now you can speak loud about "rooting".  The same thing is applied to JailBreaking.