A Hyper-V server (called the parent partition) provides its guests access to hardware and processing resources (virtualization stack). Hyper-V makes it possible to logically partition VMs into separate pieces, which includes Operating Systems and applications. The parent and child partitions are both parts of the partition. One parent partition can be run in each Hyper-V environment, and it should be a supported version of Windows Server. The parent partition can be used to run several child partitions that will host guest operating systems. Virtual devices can be used to emulate the hardware resources to which child partitions have no direct access. Parent-child partitions interaction happens via VMBus. It allows you to manage the requests delivered to virtual devices. In addition to the parent partition, the Virtualization Service Provider (VSP) is also included, enabling the connection to the VMBus to be made to manage requests from child partitions.
Hyper-V can support two kinds of Operating Systems, enlightened and unenlightened, in child partitions. Enlightened children have unique components and a VSC (Virtualization Service Client) that allows a direct connection with the virtualization layer, making them unique. At the same time, the partition for a child who is not enlightened has a more straightforward structure and emulates software.