A virtual machine snapshot is:

A backup is a separate, restorable full copy of data designed for disaster recovery, whereas a snapshot is a dependent delta record that cannot function without the original VM files.

A snapshot stores only the delta changes from the moment it is taken and preserves memory state, VM settings, and disk state, allowing an administrator to roll back the VM to that exact moment; it is not an independent copy but a revertible checkpoint tied to the live VM.

An exact copy (clone) produces a fully independent duplicate VM with its own identity, while a snapshot maintains a dependency on the parent VM and only captures changed blocks.

An image is a standalone, deployable template used to provision new VMs, not a revertible state record linked to a currently running virtual machine.