Hypervisor

Definition

A Hypervisor is software (or firmware) that creates and manages Virtual Machines (VMs) on one physical server. Its role is to sit between the physical hardware and the operating systems, sharing CPU, RAM, storage, and network resources safely.

What Problem It Solves

• Without buying many physical servers, you can run multiple servers on one machine.
• It reduces hardware cost, improves resource usage, and makes scaling, testing, and cloud hosting easier.

What Happens If Not Used

• Every operating system needs its own physical computer.
• Hardware costs, power usage, and maintenance increase significantly.

Easy Wording

A hypervisor lets one computer behave like many separate computers.

Layman Example

Think of an apartment building. The building is the physical server, the hypervisor is the building manager, and each apartment is a VM where different families (operating systems) live independently.

Technical Example

Without Hypervisor:

User → DNS → Physical Server (Ubuntu only) → Website

With Hypervisor:

User → DNS → Physical Server → Hypervisor → VM 1 (Ubuntu/Web Server) → Website

↳ VM 2 (Windows)
↳ VM 3 (Database)

The hypervisor receives the hardware resources first, then allocates them to each VM, allowing multiple isolated servers to run on one physical machine.