Microsoft Entra apps, explained
Every time you sign in to a work app with a Microsoft account, an "app" registered in Microsoft Entra is quietly doing the introductions. This site explains what those apps are, what they do and how to look after them.
The short version
Microsoft Entra ID (formerly Azure Active Directory) is Microsoft's cloud identity service. When a program wants to sign users in, or to call another service on someone's behalf, it is registered with Entra as an application. That registration gives the program an identity, the rules it must follow and the permissions it has been granted.
Entra apps are the reason you can sign in once and open many services, and the reason an organisation can see and control which programs may touch its data.
Where to go next
- What are Entra apps? The building blocks and the words people use.
- What they do Sign-in, tokens and permissions.
- Why they matter Security, single sign-on and least privilege.
- The app lifecycle From registration to retirement.
- Learn more A searchable glossary and where to read further.
Microsoft and Entra are trademarks of Microsoft. This is an independent explainer.