Authentication simply means verifying who the user is before allowing access to an app. In Power Apps, users sign in using their Microsoft work or school account, and this identity is verified through Microsoft Entra ID.
For example, when an employee opens a Power App, they log in with their company account. Once Entra ID confirms their identity, the app allows access. If that identity is not valid, then user cannot open the app. This makes sure that only authorized users can enter the application.
