In electronic computing, virtualisation is the abstract presentation of physical computer resources, such as, servers, networks, memory, storage after they have been converted, so that users can make use of these resources in a better way than their original configuration. The new virtual part of these resources is not subject to the limitations of the configuration, the geographical or physical states of the current resources. Virtualisation technology brings about several benefits: it can expand the capacity of hardware, simplify the re-configuration process of software, improve the efficiency of computers. Virtualized resources in general refer to computing power and data storage. Other virtualisation categories include: hardware virtualisation, virtual machine (VM), platform virtualisation, memory virtualisation, storage virtualisation, desktop virtualisation, database virtualisation, software virtualisation and service virtualisation.

Virtualisation is by no means a new technology: in as early as the 1960s, virtualisation was used in IBM mainframes. Virtualisation technology has improved usage efficiency of physical computer resources, equipping them of the ability to flexibly expand. In implementing virtualisation, one needs to consider how to manage and how to dynamically reshuffle virtual resources across the entire infrastructure.

In the era of Virtualisation 1.0, the emphasis was on how to reduce costs and to improve the efficiency in the use of IT resources. While bringing about convenience, virtualisation also brings about certain woes. The direction of the next steps in development of virtualisation is to adjust its flexibility to meet business development and to achieve dynamic matching of resources and services. In the process of evolution towards cloud computing, virtualisation has entered the 3.0 era.

While cloud computing and virtualisation are not tied technologies, both can complement each other if used together. Cloud computing and virtualisation can take turns in working: cloud computing solutions rely on and make use of virtualisation to provide services, and companies which have not adopted cloud computing solutions yet can still take advantage of virtualisation for better return on investment and benefits from the internal infrastructure.