What is OAuth?
Sagar Pardeshi
http://oauth.net/2/
http://www.codeproject.com/Articles/577384/Introduction-to-OAuth-in-ASP-NET-MVC
OAuth allows a user to share his data store in one side with other side without letting the other side know about the username and password of the previous site. Its similar to online payment system, where when we click on the payment we are redirected to our bank website for payment. Similarly, when we try to login to a website with other website credential we will be directed to other website.