In the early days the emphasis was on virtualisation. Organisations concentrated on increasing the number of servers on one machine using a hypervisor program with the activities kept in-house.

More recently there has been an emphasis on cloud computing, with more functions passing into the hands of a third party. The latter includes the option for a private cloud, dedicated to one enterprise.

Virtualisation and private cloud strategies are sometimes confused, not helped by the varying definitions.

The strongest distinction is that virtualised technology is a fixture of an IT estate while cloud computing is offered as an on-demand service, for platform, infrastructure or software, available on a pay-as-you-go basis.

Cloud is currently drawing more attention, with the government opening the and a stream of big deals in the private sector, recent examples being at Deloitte and .