A virtual machine (VM) is a software-based computer that replicates the functionality of a physical computer. It simulates a complete hardware environment, including CPU, memory, network interfaces, and storage, while running on a physical host system. VMs make it possible to run multiple operating systems simultaneously on a single piece of hardware. This optimizes resource utilization and increases flexibility within the IT infrastructure.
A VM works by running a guest operating system in an isolated environment. This isolation ensures that the guest operating system and its applications operate independently of the host system. This allows different operating systems, such as Windows, Linux, or macOS, to run in parallel on the same physical computer without affecting one another.
A key advantage of virtual machines is their flexibility. Companies can partition a single physical server into multiple VMs, allowing different applications or services to run on a single piece of hardware. This results in cost savings because fewer physical servers are required. In addition, resource utilization becomes more efficient because the hardware is used more effectively.
Virtual machines are often divided into two main categories: system-based and process-based VMs.
A crucial element of virtualization is the hypervisor, software that manages the VMs. There are two main types of hypervisors: Type 1 hypervisors, which run directly on the host system’s hardware, and Type 2 hypervisors, which run within a host operating system. Type 1 hypervisors offer higher performance and security because they interact directly with the hardware. Type 2 hypervisors, by contrast, are easier to implement and are ideal for development environments.
