Def. Broadly speaking, Cloud computing describes the delivery of hosted services over the internet, as opposed to traditional on-premise methods.
Such services include data storage and computing resources and have three distinct features:
1. They are sold on demand, typically by the hour.
2. They are elastic, whereby a user can utilize as much of the service as they want anytime.
3. They are fully managed by the provider (i.e: all the user needs is a personal computer, phone, tablet, etc. and internet access).