"...can provision capabilities as needed without requiring human interaction"
"Capabilities are available over the network accessed through standard mechanisms..."
In short, access from anywhere using standard mechanisms like VPNs, HTTP, HTTPs, etc.
Providers share resources to consumers. Resources are available at multiple locations, you just need to decide where to get the resource from.
Get more resources quickly as needed
Pay only for what you use. Nothing in advance.
Public Cloud = using 1 public cloud
Private Cloud = using on-premises *real* cloud (if they meet 5 essential characteristics)
Multi-Cloud = using more than 1 public cloud
Hybrid Cloud = Public and Private Clouds
Hybrid Cloud is NOT public cloud + legacy on-premises.
Hybrid Network/Environment = Public cloud + legacy on-premises