A Solaris Container is the combination of system resource controls and the boundary separation provided by zones. Zones act as completely isolated virtual servers within a single operating system instance. By consolidating multiple sets of application services onto one system and by placing each into isolated virtual server containers, system administrators can reduce cost and provide all the same protections of separate machines on a single machine.
Zones provide a new isolation primitive for the Solaris OS, which is secure, flexible, scalable and lightweight: virtualized OS services which look like different Solaris instances. Together with the existing Solaris Resource management framework, Solaris Zones forms the basis of Solaris Containers.