Container is a term that describes an isolated IT hosting environment which runs its own Operating System (OS) alone, which might or might not be a different type of OS than the one of the underlying physical server (infrastructure). Unlike the other Virtual Servers (Virtual Machines), the so-called Containers are created through a virtualization technique called OS Virtualization. It is a software assisted virtualization, which allows any computer hardware to run multiple instances with separate OS concurrently.

The instances (VEs), also containers, work like a separate, real computers. Any software application running on a standard  Operating System can use all resources – CPU power, memory and other computing resources as well as files and folders – of a Container based computer.

Containers crated thought an OS Operating virtualization does not feature the same level of flexibility as the Virtual Machines created with full virtualization, for example. A Container cannot use an OS different from the one that runs on the underlying physical server, or a different guest kernel. If the underlying host runs any Linux distribution, the Containers that run on top of it cannot run Windows.