Cloud computing is a type of internet-based computing that provides shared computer processing resources and data to computers and other devices on demand.

It is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.

Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over an electrical network.

In the end, it comes down to what a business needs and how they want to access computing resources. The cloud model is composed of five essential characteristics, three service models, and four deployment models.