Why Do I Need A Vpn? 

A vpn  secures your mobile/computer's internet connection to guarantee that all of the data you're sending and receiving is encrypted and secured from prying eyes, and also its a way to bolster your security and access resources on a network you're not physically connected to

Whether the VPNs you're familiar with are the ones offered by your school or business to help you work or stay connected when you're traveling or the ones you pay to get you watch your favorite shows in another country as they air, they're all doing the same thing. For much more detail on what VPNs are, how they work, and how they're used, 
see more here..