OAuth and OpenID are two popular authentication protocols that are widely used for authorization and authentication purposes. Both protocols allow users to securely sign in to a website or application without revealing their passwords. However, they have different purposes and uses, and it’s essential to understand the key differences between the two. In this article, we’ll take a closer look at OAuth and OpenID and compare them in detail. Authorization or Authentication OAuth (Open Authorization) is an authorization protocol that enables third-party applications to access user data without revealing their passwords.