Which component is essential for the iCloud Drive functionality?

For iCloud Drive functionality, an active internet connection is crucial. iCloud Drive is designed to allow users to store files and access them across multiple devices using Apple’s cloud services. Without an active internet connection, your device cannot communicate with iCloud servers to upload or download files. This means that even if you have a registered Apple ID, a compatible device, and adequate iCloud storage space, without internet access, you wouldn't be able to use the service effectively. Therefore, having a reliable internet connection is foundational for iCloud Drive to function as intended, enabling seamless synchronization and accessibility of files across devices.