Cloud

In brief

Instead of buying your own computers, you rent someone else’s processing power and storage space via the internet, and you only pay for what you use. It’s a bit like metered electricity, but for computing.

▶ Precise definition

A model for the provision of IT resources (computing, storage, networking, software) on demand, shared and billed on a pay-as-you-go basis, and operated by a third party. Three levels: IaaS (raw infrastructure), PaaS (execution platform), SaaS (ready-to-use software). The higher up the levels you go, the more you delegate operational management, and the more access to your data you entrust to others.