Operating System-Level Virtualization
Sometimes referred to as OS virtualization, this method separates one computer operating system into multiple isolated user spaces called virtual environments (VE), or containers.
These are also sometimes called virtual private serves (VPS). OS virtualization makes it so applications will not interfere with one another.
OS virtualization is different from the traditional VM, or virtual machine, method because VM will only support the same operating system within each section rather than multiple operating systems running together.
This traditional VM method requires operating systems to communicate through an abstraction layer to the hardware and when there are more VMs running the whole system slows.
OS virtualization partitions can be much smaller and more are able to run at the same time without losing speed. This is due to the fact they run off the same hardware configuration, i.e. every VE exist in a single machine.