A hypervisor is a software layer that allows multiple operating systems to run on a single physical machine. It creates and manages virtual machines (VMs), enabling each VM to operate independently as if it were a separate computer. This technology is essential for efficient resource utilization and is widely used in data centers and cloud computing. There are two main types of hypervisors: Type 1 (bare-metal) runs directly on the hardware, while Type 2 (hosted) runs on top of an existing operating system. Popular hypervisors include VMware, Microsoft Hyper-V, and KVM.