Tech in Diagrams

IaaS vs PaaS vs SaaS

The three service models differ in one thing: how much of the stack the provider operates for you.

Beginner 5 min Cloud Computing
Service models · responsibility stack
  • You manage
  • Provider manages
THE STACKTop of stack — closest to peopleData & configurationContent · identities · settingsApplicationThe software people useRuntime & middlewareLanguage runtime · web serverOperating systemPatching · hardeningVirtualisationHypervisor · poolingPhysical infrastructureRacks · network · power · coolingBottom of stack — the hardware01On-premisesYou run everythingYou manageData & configurationYou manageApplicationYou manageRuntime & middlewareYou manageOperating systemYou manageVirtualisationYou managePhysical infrastructure02IaaSRent compute, storage, networkYou manageData & configurationYou manageApplicationYou manageRuntime & middlewareYou manageOperating systemProvider managesVirtualisationProvider managesPhysical infrastructure03PaaSDeploy code, not serversYou manageData & configurationYou manageApplicationProvider managesRuntime & middlewareProvider managesOperating systemProvider managesVirtualisationProvider managesPhysical infrastructure04SaaSUse finished softwareYou manageData & configurationProvider managesApplicationProvider managesRuntime & middlewareProvider managesOperating systemProvider managesVirtualisationProvider managesPhysical infrastructure
Moving right, more of the stack is operated by the provider — but data, identities and configuration always stay with the customer.

Hover a layer or a service model to highlight who operates it; click for a short explanation.

Why it matters

  • Choosing a model is choosing how much operational work your team keeps.
  • Responsibility for data and access control never transfers to the provider, whatever the model.
Next conceptWhat is a Virtual Machine?A virtual machine is a software-defined computer that shares one physical host with other isolated machines.