What is child partition?
A child partition is a logical hard drive division in the Microsoft Hyper-V environment that runs an isolated operating system.
The child partition is one of three possible types in the Hyper-V environment. The other two are the root partition and the parent partition. (However, in Microsoft Hyper-V version 1.0 the root and parent partitions are the same entity.) There can be only a single parent partition on a given machine; the number of possible child partitions depends on available computing resources.Content Continues Below
Each partition is allocated its own memory and processor resources and maintains policy information about device use. The root partition, which can access memory and devices directly, starts the hypervisor. The parent partition runs the hypervisor and creates and manages child partitions. Each child partition can run a separate OS, which is sometimes known as a Guest OS.
A virtual machine is a type of child partition.