The whole idea behind taking a snapshot is to save the current state of the virtual machine so that it will remain unaffected by the changes you intend to make. In a situation where you want to discard the changes you just made and return to the saved state of the virtual machine, the revert to latest snapshot operation is performed.
Reverting to the current Virtual Machine Snapshot
Getting ready
Reverting to the current snapshot will discard the most recent changes and is an irreversible operation, and so it is important to gather your thoughts before you proceed. This process does not require the use of the snapshot manager for the virtual machine.