Virtual Machine (VM)

A Virtual Machine (VM) is a software-based emulation of a physical computer that runs operating systems and applications as if on real hardware. Virtual machines allow multiple operating systems to operate simultaneously on a single physical machine, enabling better utilization of resources and isolation between different environments.

Each VM contains its own virtual hardware, including CPUs, memory, storage, and network interfaces, abstracted from the underlying physical infrastructure by a hypervisor. Hypervisors are either software-based (Type 2, running on a host OS) or hardware-based (Type 1, running directly on the physical hardware).

Virtual machines are widely used in software development, testing, and deployment because they provide a controlled environment. Developers can replicate specific setups, run incompatible software, or safely test updates without affecting the host system. VMs are also central to cloud computing, powering Infrastructure-as-a-Service (IaaS) solutions offered by providers like AWS, Azure, and Google Cloud.

Benefits of VMs include scalability, cost efficiency, and improved disaster recovery through snapshot backups. However, they may incur performance overhead compared to running directly on hardware.