What problem does OAuth2.0 solve ?

OAuth2.0 enables third-party client applications to gain delegated access to an end user’s data and actions without having to share the end user’s credentials to the third-party client application.

How it works?

The basic flow involves the client application to request authorization from the resource owner, which is usually in the form of a token. This token can then be used by the client application to “do” things on behalf of the resource owner.

Terminology

1. Client Application

   The third-party application that wants to consume the resources exposed by a resource server or a group of them.

2. Resource Server

   The server whose resources are being exposed and need to be protected.

3. Resource Owner

   The owner of a particular resource in the resource server. This is also known as the end user.

4. Authorization Server

   The server that protects the resources of the resource owner and facilitates the delegation of access to the client application.