What does OAuth provide?

OAuth, which stands for Open Authorization, provides a standard method for clients (like web or mobile apps) to access server resources on behalf of a resource owner (like a user). It also provides a process for end-users to authorize third-party access to their server resources without sharing their credentials (typically, a username and password pair), using user-agent redirections.

Here are the steps OAuth provides:

1. The client requests authorization from the resource owner. The request includes the type of resources the client wants to access and what it wants to do with those resources.

2. The resource owner authorizes the request and sends the client an authorization grant.

3. The client requests an access token from the authorization server (which could be the same server as the resource server or a separate one) by presenting its own credentials and the authorization grant.

4. If the application’s credentials are valid and the authorization grant is valid, the authorization server issues an access token to the application. Authorization is complete.

5. The client requests the resource from the resource server and presents the access token for authentication.

6. If the access token is valid, the resource server serves the resource to the client.

In summary, OAuth provides a secure and standardized method for authorization in a simple and consistent manner across different software applications.