Virtualization is the correct answer because it refers to the creation of virtual versions of physical components, such as servers, where each virtual server, known as a virtual machine, operates in an isolated environment on the same hardware. Containerization involves encapsulating an application and its dependencies into a container with its own runtime environment, but it does not create separate operating systems. Serverless computing abstracts the server layer, with the cloud provider dynamically managing the allocation of machine resources. High availability refers to systems that are designed to operate continuously without failure for a long period of time, but it is not a technology for running multiple operating systems on the same hardware.