Hey @wilma, thank you for reaching out to us.
User Enrollment allows for a personal and a Managed Apple ID to exist on the same device. The existing personal Apple ID is used for the user’s personal iCloud data, while the Managed Apple ID provided by your organization will be used to store all of the organization’s corporate iCloud data in the company’s managed iCloud Drive. Apple has provided such as system to ensure that the users have autonomy over their devices, while the corporate data is stored securely.
Hope this helps alleviate your concerns.
Regards
Eren Schwarz
Hexnode UEM