How does authentication work with Azure AD?

Short answer: Users authenticate via OAuth 2.0 / OpenID Connect. Azure AD issues tokens (ID token, access token, refresh token). Tokens are validated by the app to authorize access.

Real-world example (ShopNest)

ShopNest on Azure typically uses App Service + SQL Database + Blob Storage + Application Insights for monitoring.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.