What is the primary function of a VM snapshot?

The primary function of a VM snapshot is to save the current state of a VM. This includes capturing the virtual machine's memory, settings, and the state of all virtual disks at a specific point in time. Snapshots are particularly useful for various scenarios, such as testing new software or system changes, allowing administrators to revert to a stable state if something goes wrong.

Additionally, this capability makes it easier to troubleshoot issues or perform updates without risking data loss, thus enhancing the management and maintenance of the VM lifecycle. Although the other options present related concepts in virtualization, they do not accurately reflect the specific function of a snapshot as it pertains to capturing the existing state of the virtual machine for later recovery or reference.