Virtualization is a technique used in cloud computing to create a virtual ecosystem of storage devices and server operating systems. It allows users to run multiple operating systems on a single physical machine at the same time, increasing the utilization and flexibility of hardware. Virtualization is the process of creating virtual representations of servers, storage, networks, and other physical machines. It uses specialized software, called a hypervisor, to create several cloud instances or virtual machines on one physical computer.

Virtualization technology makes cloud computing possible. Cloud providers set up and maintain their own data centers, creating different virtual environments that use the underlying hardware resources. Users can then program their systems to access these cloud resources by using APIs. Virtualization allows sharing of a single physical instance of a resource or an application among multiple customers and organizations at one time.

Virtualization is often synonymous with hardware virtualization, which plays a fundamental role in efficiently delivering Infrastructure-as-a-Service (IaaS) solutions for cloud computing. It is a cost-effective, hardware-reducing, and energy-saving technique used by cloud providers.

In summary, virtualization is a technique used in cloud computing to create virtual representations of servers, storage, networks, and other physical machines. It allows multiple operating systems and applications to run on the same machine and its same hardware at the same time, increasing the utilization and flexibility of hardware. Virtualization technology makes cloud computing possible and is a cost-effective, hardware-reducing, and energy-saving technique used by cloud providers.