Virtualization is a partitioning of a single physical server into multiple logical servers.

Para-virtualization is a virtualization technique that presents a software interface to the virtual machines which is similar, yet not identical to the underlying hardware–software interface. Paravirtualization (PV) is an enhancement of virtualization technology in which a guest operating system (guest OS) is modified prior to installation inside a virtual machine (VM) in order to allow all guest OS within the system to share resources and successfully collaborate, rather than attempt to emulate an entire hardware environment. Full virtualization is a virtualization technique used to provide a VME that completely simulates the underlying hardware. network virtualization is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Hardware-assisted virtualization is a platform virtualization approach that enables efficient full virtualization using help from hardware capabilities, primarily from the host processors

→Cloud computing is the delivery of computing services—servers, storage, databases, networking, software, analytics, intelligence and more—over the Internet (“the cloud”) to offer faster innovation, flexible resources and economies of scale.
→Most cloud computing services fall into four broad categories: infrastructure as a service (IaaS), platform as a service (PaaS), serverless and software as a service (SaaS).