What type of virtualization allows for multiple operating systems to run on a single physical server?

Server virtualization is the correct answer as it specifically allows for multiple operating systems to operate on a single physical server. This is achieved through hypervisor software that creates and manages virtual machines (VMs). Each VM can run its own operating system and applications independently, allowing for efficient resource utilization and flexibility. Server virtualization enables organizations to maximize their investment in physical hardware by consolidating workloads and isolating operating systems from each other, leading to simplified management and reduced costs.

In contrast, storage virtualization focuses on abstracting physical storage resources to present them as a single pool, enhancing storage management but not directly enabling multiple operating systems. Network virtualization involves combining hardware and software network resources into a single, flexible virtual network but does not facilitate the running of multiple OS instances. Application virtualization allows applications to run on a device without being installed directly on the operating system, but it doesn't involve running multiple OS environments within a single physical server.