VMs are configured by default to take daily snapshots. They contain a live snapshot of the data on the disk when the snapshot was taken. These snapshots are maintained for 7 days before being deleted.
These snapshots are not meant to be an offsite backup of your VM, they are stored on the same disk as your VMs disk. They do allow for quick recovery incase of loss of data (intentional or accidental) and allow your VM to continue working for you.
We are working on getting an automated processes to allow you to choose a snapshot of your VMs disk to rollback to. However for now, create a ticket with the VM and date, and we will manually roll it back for you.
NOTE: This does include some downtime as the VM will need to be shutoff, the snapshot restored, and the VM booted. Live rollbacks are not supported.