A hypervisor, also known as a virtual machine monitor (VMM), is software that creates and manages virtual machines (VMs) on a host system. The hypervisor enables multiple operating systems to run concurrently on a single physical machine by abstracting the hardware resources, such as CPU, memory, and storage, and allocating them to each VM. There are two types of hypervisors: Type 1 (bare-metal), which runs directly on the host's hardware, and Type 2 (hosted), which runs on top of a conventional operating system. Type 1 hypervisors, like VMware ESXi and Microsoft Hyper-V, are typically used in enterprise environments for server virtualization, while Type 2 hypervisors, like Oracle VirtualBox and VMware Workstation, are often used for development and testing purposes.

Hypervisors play a crucial role in modern IT infrastructure, enabling efficient utilization of hardware resources, reducing costs, and simplifying management through virtualization. By isolating each virtual machine, hypervisors enhance security, as issues in one VM do not affect others. Hypervisors are also foundational to cloud computing, as they allow cloud providers to offer scalable, multi-tenant environments where multiple customers can share the same physical resources without interfering with each other. As virtualization continues to evolve, hypervisors remain a key technology in data centers, development environments, and cloud platforms.