Hi @Rando, Thomas Anthony , from my colleague @Marilee Turscak-MSFT :
Azure App Service authentication is built-in (easy auth) authentication for Azure. It is a pre-made authentication and authorization solution that helps make sure that best practices are followed and kept up-to-date. It's so that users don't have to write any authentication code. It can be used with either Azure AD or Azure AD B2C. B2C is about letting users sign in with their separate social identities and is for consumers who do not require access to internal resources and it can be used with Azure App Service authentication but doesn't have to be.
Please let me know if you have any questions!
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