Container and Full Virtualization
From Proxmox VE
Proxmox VE is optimized for performance and usability. For maximum flexibility, the following virtualization technologies are installed by the bare metal ISO-installer.
Container Virtualization (OpenVZ)
This is the preferred technology for running Linux servers as it is the fastest approach. OpenVZ is container-based virtualization for Linux. OpenVZ creates multiple secure, isolated containers (otherwise known as CT, VEs or VPSs). Each container performs and executes exactly like a stand-alone server; a container can be rebooted independently and have root access, users, IP addresses, memory, processes, files, applications, system libraries and configuration files.
Currently all Virtual Appliances are OpenVZ based and are "production ready".
For details see OpenVZ.
Full Virtualization (KVM)
KVM (for Kernel-based Virtual Machine) is a full virtualization solution on x86 hardware containing virtualization extensions (Intel VT or AMD-V CPU is needed). Each virtual machine has private virtualized hardware: a network card, disk, graphics adapter, etc. KVM is a similar to XEN, but KVM is part of Linux and uses the regular Linux scheduler and memory management.
KVM is perfectly suited to unmodified operating systems including windows operating systems like Windows 2000, Windows XP, Windows Vista, Windows 7 and 8, Windows Server 2000/2003/2008/2008r/2012.
For details see KVM.
KVM supports paravirtualization for device drivers to improve I/O performances. See Paravirtualized Network Drivers for Windows.
For all details see KVM.