Tethering is the act of sharing your phone’s mobile data connection with another device — such as your laptop or tablet — connecting it to the Internet through your phone’s data connection. There are several ways to tether on Android.

Tethering is useful when you’re somewhere where you don’t have Wi-Fi access, do have cellular data access, and want to do something on your computer instead of your phone. But you may pay extra for the convenience.

via How-To Geek http://www.howtogeek.com/170302/the-htg-guide-to-tethering-your-android-phone/