Reference:
https://docs.microsoft.com/en-us/microsoft-365/compliance/compliance-manager?view=o365-worldwide

When you register an application through the Azure portal, an application object and service principal are automatically created in your home directory or tenant.
Reference:
https://docs.microsoft.com/en-us/azure/active-directory/develop/howto-create-service-principal-portal

Explanation
https://docs.microsoft.com/en-us/azure/active-directory/privileged-identity-management/pim-configure Privileged Identity Management provides time-based and approval-based role activation to mitigate the risks of excessive, unnecessary, or misused access permissions on resources that you care about. Here are some of the key features of Privileged Identity Management: Provide just-in-time privileged access to Azure AD and Azure resources Assign time-bound access to resources using start and end dates Require approval to activate privileged roles Enforce multi-factor authentication to activate any role Use justification to understand why users activate Get notifications when privileged roles are activated Conduct access reviews to ensure users still need roles Download audit history for internal or external audit Prevents removal of the last active Global Administrator role assignment