What is the USB OTG
USB OTG (USB On-The-Go) is a standard that enables mobile devices to talk to one another. And that's not all USB OTG can do. By enabling your device to act as a USB host – that is, to be the boss of other devices that you connect to it – you can use additional hardware devices such as USB flash drive storage, a keyboard, mouse or game controller.
Just plug in a USB mouse and you will automatically see its cursor appear on your display. This is also a great way to use your device if you break or crack the touchscreen (which is not covered under the warranty)