What is virtualization?

Virtualization is a technology that enables a single server to act as many. Solutions such as VMware’s Virtual Infrastructure work  by,  in  effect,  converting  hardware into software. This is achieved by the creation of virtual machines  (VMs) which VMware  describe  as, “Tightly isolated software containers that can run their own operating systems and applications as if they were physical  computers. A VM behaves exactly  like a physical computer and contains  it own virtual (software-based) CPU, RAM, hard disk and network interface card (NIC).” In other words, a VM is simply a computer that has been converted  entirely  into  software  and  packaged  into  a single file.

The  fact  that each VM has  its own virtual CPU, NIC, etc., means  that  it can be run on practically any hardware - even hardware on which other VMs are running. Accordingly, virtualization breaks  IT’sone-application per-server model by enabling multiple heterogeneous operating systems to be simultaneously run on the same physical server.