Definition
Virtual machines, or VMs, are software based emulations of physical computer systems. They allow a single physical server to host multiple independent operating systems and applications, each running in its own isolated environment. This isolation is achieved through a hypervisor, which manages the allocation of physical resources like CPU, memory, and storage to each VM. VMs are crucial for efficient resource utilization, enabling organizations to run diverse workloads on less hardware and reducing operational costs. For instance, a company might use VMs to host different operating systems for development, testing, and production environments on the same server. Unlike containers, which share the host OS kernel, VMs provide a full hardware virtualization, offering greater isolation but requiring more resources. Understanding VMs is fundamental for cloud computing, system administration, and cybersecurity domains, appearing on exams like AWS SAA and CompTIA Network+.