In cloud computing, what does "virtualization" refer to?

Virtualization is fundamentally about creating a virtual version of physical hardware components, which allows a single physical server to host multiple virtual servers. This process is key to maximizing resource utilization, improving scalability, and enabling efficient management of IT resources in a cloud computing environment. By abstracting the underlying physical hardware, virtualization allows for the creation of isolated environments that can run different operating systems and applications, all while sharing the same physical infrastructure. This leads to increased flexibility and agility in deploying and managing services in the cloud.

The other options do not accurately capture the concept of virtualization. Copying data refers to data management rather than the virtualization process itself. Securing data on a private server involves security practices, which is a separate focus from the virtualization of hardware. Isolating user access levels is more about security and permissions rather than the creation of virtual resources. Thus, the choice referring to the creation of a virtual version of physical hardware components correctly encapsulates the essence of virtualization in cloud computing.