- A public cloud (the clue is in the name) is open to the public.
- A private cloud (the clue is in the name) is private to some set of people.
- external to you and therefore controlled, operated and run by another party.
- internal to you which means it is controlled, operated and run by yourself.
- AWS offers a public cloud which is external to everyone but Amazon.
- Eucalyptus offers technology for a company to build a private cloud which is internal to that company.
-- 5th January 2017
In 2017, there still exists a surprising view that private cloud is more than transitional. Whilst Amazon, Google and Canonical have emerged as major players (in the case of Amazon, a Titan) the story of OpenStack and Rackspace was less rosy. A mix of poor strategic gameplay led to OpenStack becoming firmly entrenched in the private cloud space and though it move up the stack a bit, it never moved into the platform space. That charge has been left to Cloud Foundry which is now facing off against Amazon's effort - Lambda. Rackspace lost the public cloud battle but it has re-invented itself around Amazon.