OAuth is a commonly used standard by many application developers. It specifies a process for resource owners to authorize third parties access to their server resources without sharing their credentials. Clients use the access token to grant access to the protected user data. The process that the client grant the access token is known as grant type. 1)Authorization code grant type Figure 1 Can use to obtain both access token and refresh tokens.The flow of authorization code grant type is as follows.When user authorize the third party app to access data, the app request for authorization . Then the authorization server authenticates the resource owner.The access token is sent to client application as the response. The client app request for the access token, using the authorization code. The client app get receive the access token as the respones. 2) Implicit grant type Figure 2 Client is not a...