This glossary defines terms and spells out abbreviations used in Parallels Cloud Server documentation. References to terms defined elsewhere in the glossary appear in italics.
Application template. A template used to install a set of applications in Containers. See also Template.
Container (or regular Container). A virtual private server, which is functionally identical to an isolated standalone server, with its own IP addresses, processes, files, users database, configuration files, applications, system libraries, and so on. Containers share one Parallels server and one OS kernel. However, they are isolated from each other. A Container is a kind of ‘sandbox’ for processes and users.
Guest operating system (Guest OS). An operating system installed inside a virtual machine and Container. It can be any of the supported Windows or Linux operating systems.
Hardware virtualization. A technology allowing you to virtualize physical servers at the hardware level. Hardware virtualization provides the necessary environment for creating and managing Parallels virtual machines.
Operating system virtualization (OS virtualization). A technology allowing you to virtualize physical servers at the operating system (kernel) level. OS virtualization provides the necessary environment for creating and managing Parallels Containers.
OS template (Operating System template). A template used to create new Containers with a pre-installed operating system. See also Template.
Package set. See Template.
Parallels server (physical server or server). A server where the Parallels Cloud Server software is installed for hosting Parallels virtual machines and Containers. Sometimes, it is marked as Container 0.
Parallels Cloud Server license key. A license key that you should install on the physical server to use Parallels Cloud Server. Every physical server must have its own key installed.
Parallels Cloud Storage license key. A license key for Parallels Cloud Storage to use its functionality.
Memory and IOPS deduplication. A feature introduced in Parallels Cloud Server 6.0. By caching identical files in multiple Containers it helps save memory and IOPS on the Hardware Node.
Parallels Virtuozzo Containers for Linux. An operating system virtualization solution allowing you to create multiple isolated Containers on a single physical server to share hardware, licenses, and management effort with maximum efficiency.
Private area. A part of the file system storing Container files that are not shared with other Containers.
Template (package set). A set of original application files (packages) repackaged for mounting. There are two types of templates. OS Templates are used to create new Containers with a pre-installed operating system. Application templates are used to install an application or a set of applications in Containers.
UBC. An abbreviation of User Beancounter.
User Beancounter. The subsystem of the Parallels Cloud Server software for managing Container memory and some system-related resources.
Virtual Environment (VE). An obsolete designation of a Container.
Virtuozzo File System (VZFS). A virtual file system for legacy Containers.
Virtual machine (VM). A computer emulated by Parallels Cloud Server. Like a Container, a virtual machine is functionally identical to an isolated standalone computer, with its own IP addresses, processes, files, users database, configuration files, applications, system libraries, and so on. However, unlike Containers, virtual machines run their own operating systems rather than sharing one operating system kernel.