Authentication and authorization using OAuth
Azure AD is an identity provider that can authenticate users based on already available users and service principals available within the tenant. Azure AD implements the OAuth protocol and supports authorization on the internet. It implements an authorization server and services to enable the OAuth authorization flow, implicit as well as client credential flows. These are different well-documented OAuth interaction flows between client applications, authorization endpoints, users, and protected resources.
Azure AD also supports single sign-on (SSO), which adds security and ease when signing in to applications that are registered with Azure AD. You can use OpenID Connect, OAuth, SAML, password-based, or the linked or disabled SSO method when developing new applications. If you are unsure of which to use, refer to the flowchart from Microsoft here: https://docs.microsoft.com/azure/active-directory/manage-apps/what-is-single-sign-on#choosing...