Hypervisor

A hypervisor (also Virtual Machine Monitor, VMM) sits between the physical hardware and the guest operating systems and distributes CPU time, RAM, storage and network I/O across multiple virtual machines. Two types exist: type 1 (bare-metal, runs directly on hardware — KVM, Xen, VMware ESXi, Microsoft Hyper-V) and type 2 (runs as an application on a host OS — VirtualBox, VMware Workstation). Production-grade VPS and cloud platforms use only type-1 hypervisors for lower latency and stronger isolation. Invisible to you as a customer — but it matters once CPU sub-types (AMD EPYC vs Intel Xeon), nested virtualisation or hardware passthrough come into play.