Cloud Service Models

Cloud providers in general and Vmware in particular defines at least three typical vCloud service models.

• Infrastructure as a Service IaaS
  • Flexible environment: customers have complete control over the VMs on which their applications run
  • customers are responsible for OS patching and VM maintenance
  • two services emerged from the IaaS: Desktop as a Service (DaaS) and Disaster Recovery as a Service (DRaaS)
• Platform as a Service PaaS
  • useful for web hosting
  • stable environment
  • PaaS Providers are responsible for patching and upgrading the underlying OS, which is sometimes a slow process
  • customers can customize how their applications work
• Software as a Service SaaS
  • are provided by SaaS Providers
  • applications must be available to customers anytime, anywhere
  • examples: Google Gmail, Zimbra
  • customers are not concerned by how these applications work
  • customers should be able to customize the look and feel of their applications