[1] The force driving server virtualization is similar to that which led to the development of time-sharing and multiprogramming in the past.
[citation needed] The physical server typically runs a hypervisor which is tasked with creating, releasing, and managing the resources of "guest" operating systems, or virtual machines.
Unmetered hosting is generally offered with no limit on the amount of data transferred on a fixed bandwidth line.
Unlimited hosting is also commonly marketed but generally limited by acceptable usage policies and terms of service.
Offers of unlimited disk space and bandwidth are always false due to cost, carrier capacities, and technological boundaries.