Virtual machines (VMs) provide the flexibility and capabilities required to meet the described requirements. VMs can easily migrate between data centers, save and restore their state, and support various operating systems and GUIs.

Migration: VMs can be moved from one physical server or data center to another, providing high flexibility in resource management.

State Saving: VMs support saving the operational state (snapshots), allowing quick recovery or migration.

Support for GUIs: VMs can run different operating systems, including those with graphical user interfaces (GUIs) like Windows and Linux.

Hardware Utilization: VMs enable better utilization of hardware resources by running multiple VMs on a single physical host.