A virtual machine (VM) is a software-based simulation of a physical computer. It runs an operating system and applications just like a real machine, but it exists as an isolated environment on a host system. Virtualization software, called a hypervisor, manages these VMs by allocating hardware resources such as CPU, memory, and storage from the host.
VMs are widely used in cloud computing, software testing, and server consolidation. They allow multiple operating systems to run on a single physical server, improving efficiency and reducing costs. Developers often use VMs to test applications in different environments without needing separate hardware.
Key benefits include:
- Isolation: VMs are sandboxed; issues in one do not affect others.
- Flexibility: Snapshots and cloning make it easy to revert or duplicate configurations.
- Portability: VMs can be moved between hosts easily.
Despite their advantages, VMs consume more resources than container-based alternatives. However, they remain a cornerstone of modern IT infrastructure.