Where the resources sit.
PUBLIC CLOUD
Shared infrastructure operated by a provider, used by many customers.
What most people mean by cloud.
PRIVATE CLOUD
Infrastructure dedicated to one organisation, whether on their premises or hosted.
Expensive, and justified only by specific requirements.
HYBRID
A combination: some workloads in public cloud, some elsewhere.
WHAT DRIVES THE CHOICE
Cost Control requirements Regulatory obligations Existing investment Latency to users
WHAT SMALL BUSINESSES ALMOST ALWAYS USE
Public cloud services.
WHAT HYBRID LOOKS LIKE PRACTICALLY
A local server for files, with cloud services for email and applications.
Most small businesses are hybrid without calling it that.
WHAT MULTI-CLOUD MEANS
Using several providers.
WHY PEOPLE DO IT
Avoiding dependence on one, or using each for its strengths.
WHAT IT COSTS
Complexity, which itself causes problems.
WHAT TO AVOID
Complexity chosen for its own sake.