The essential characteristics and the service models are well understood and well accepted. The deployment models deserve some additional discussion.
From an accessibility point of view, the private, community, public and hybrid deployment models share the following structural properties [All cloud deployments are multi-subscriber; multiple users provide the strength of cloud computing economics]:
- Private clouds are dedicated [to one enterprise], but multi-subscriber [to enterprise's employees and/or partners].
- Some cloud deployments are multi-tenant and multi-subscriber; most of the public clouds fall into this category. And, one can imagine private clouds hosted on public IaaS clouds.