# Ubiquitous language
**Project** The customer or tenant that owns the servers, backups and periodic backups.
**Server** Is the subject of a backup or periodic backup. It has one or more disks assigned.
**Disk** Can either be a local storage disk or shared storage volume. It is attached to a server and can be referenced by its name.
**Backup** Is a snapshot in time of a server. It can be used to restore a server to how it was exactly at that moment in time.
**PeriodicBackup** Is a group of servers that will be backed up periodically.