Applications registered in Azure Active Directory (Azure AD) are associated automatically to a what?

Applications registered in Azure Active Directory (Azure AD) are automatically associated with a service principal. A service principal is an identity created for use with applications, hosted services, and automated tools to access Azure resources. When an application is registered in Azure AD, a corresponding service principal is created in the tenant, which acts as a security identity for the application and enables it to authenticate and interact with other Azure services securely.

This association allows the registered application to leverage access control and permissions configured in Azure AD. For example, it can be granted specific roles and access rights required to perform its intended functions while ensuring that security principles are maintained. The service principal thus serves as a bridge between the application and the various resources it needs to interact with in a secure manner, simplifying the process of managing permissions across the Azure ecosystem.

Other options do not align with this functionality: a guest account pertains to external users, a managed identity is specifically tied to Azure resources for authentication, and a user account is associated with individual users, not applications.