3.8. Virtualization

💡 First Principle: Virtualization allows multiple virtual machines to share a single physical host's hardware. Each VM believes it has dedicated hardware—its own CPU, memory, storage, and NICs—but these are abstractions managed by the hypervisor. Virtualization multiplies efficiency: one physical server can run dozens of VMs. But it also multiplies risk: one physical host failure takes all its VMs offline simultaneously.

The exam tests virtualization from the administrator's perspective: how VMs are networked, how resources are allocated, and the trade-offs of different cloud models.