Cloud is used to describe a bunch of things, but the most important things to me are the following:
- It abstracts capacity planning away
- It provides an API and/or is internet accessible
- It is to some degree managed. Hopefully automatically.
Cloud is distinguished from other types of hosting usually by it’s massive idle capacity which allows it to scale to loads on demand as needed as well as it’s managed nature which abstracts away more difficult tasks such as performing zero-down-time deployments of services or upgrades of databases.
Examples: AWS, Google Cloud, and Azure. Sometimes also includes others like Digital Ocean, Linode, RackSpace, and Hetzner.