Citirix XenServer is a hypervisor platform that enables the creation and management of virtualized server infrastructure. It is developed by Citrix Systems and is built over the Xen virtual machine hypervisor. XenServer provides server virtualization and monitoring services. It is available in a 64-bit hypervisor platform and can be executed on the entire x86 series of processors.
Techopedia explains Citrix XenServer
Cirtix XenServer is among the virtualization solutions provided by Citrix Systems, which consolidates a physical server's computing power into multiple virtual machines, all emulating as a standard server. Citrix XenServer is built to provide the operational requirements of a standard server and supports most server operating systems, such as Linux and Windows Server, on guest server machines.
Through its virtual machine monitoring component, Citrix XenServer manages the allocation and distribution of physical server computing resources among virtual machines and administers their performance and use.