What are the cloud service models?
An essential part of understanding clouds is understanding the three cloud service models:
- Infrastructure as a Service (IaaS): This is the most fundamental service model, where a customer can select the virtual machine size (in terms of the amount of CPU and memory), select a pre-configured operating system, and deploy software inside the virtual machine instance according to business needs (services such as Amazon EC2, Azure Virtual Machines, and Google Compute Engine).
- Platform as a Service (PaaS): This type of service model varies from managed database services to managed application services (where a customer can import code and run it inside a managed environment) and more (services such as AWS Elastic Beanstalk, Azure Web Apps, and Google App Engine).
- Software as a Service (SaaS): This is the most widely used service model – a fully managed software environment where, as a customer, you usually open a web browser, log in to an application, and consume services. These could be messaging services, ERP, CRM, business analytics, and more (services such as Microsoft Office 365, Google Workspaces, Salesforce CRM, SAP SuccessFactors, and Oracle Cloud HCM).
Understanding the cloud service models will allow you to understand your role as a customer, explained later in the What is the shared responsibility model? section.
