Differences between IaaS, PaaS and SaaS

Over the last few years working as an SA i’ve helped to architect solutions that use more and more cloud services and very often see the following terms used:

  • IaaS or Infrastrcture as a Service
  • PaaS or Platform as a Service
  • SaaS or Software as a Service

Just from looking at the names of each service types, most technical people can work out what is provided by each. But unfortunately sometimes people are unsure of the differences, paticularly where IaaS ends and PaaS starts.

So i thought i’d put together a simple illustration which may help someone looking for a quick overview of the differences.

IaaS PaaS SaaS
Applications Applications Applications
Data Data Data
Runtime Runtime Runtime
Middleware Middleware Middleware
Virtualisation Virtualisation Virtualisation
Servers Servers Servers
Storage Storage Storage
Networking Networking Networking
  • Managed by vendor
    ** You manage