What must a user have to be able to upgrade macOS on their iMac?

To upgrade macOS on an iMac, a user must have admin privileges. Admin privileges provide the necessary permissions to install software, make system changes, and perform upgrades that affect the overall system. Upgrading the operating system is considered a significant change, which typically requires elevated permissions to ensure that the user has the authority to carry out such actions.

Volume ownership primarily pertains to file and disk permissions rather than the ability to upgrade the operating system. While having control over the storage volume is important for accessing files, it does not directly relate to executing an operating system upgrade.

An Apple ID authorization is relevant for downloading software from the Mac App Store and accessing certain features that require an Apple ID, but it does not grant the necessary system-level privileges to initiate a macOS upgrade on its own.

Remote management access allows someone to manage the device from a different location but does not inherently provide the local permissions needed to perform an upgrade. It is often used in enterprise environments to oversee devices but does not substitute for admin privileges on the machine itself.

Thus, having admin privileges is the essential requirement to perform a macOS upgrade on an iMac.