There are multiple providers for the OAuth 2.0 and OpenID Connect 1.0 specifications. Azure Active Directory (AAD) is one of them. AAD provides organizations with enterprise-grade identity management, for cloud applications. AAD integration will give your users a streamlined sign-in experience, and it will help your application conform to the IT policy. AAD provides advanced security features, such as multifactor authentication, and it scales really well with application growth. It is used in all Microsoft Azure Cloud products, including Office 365, and it processes more than a billion sign-ins per day.
One more interesting aspect of traditional .NET environments is that they can integrate their organizational Windows Server Active Directory with AAD really well. Here, we've used OAuth/OIDC, since we adapted Active Directory Federation...