LEARN. PRACTICE. GROW.Understand the concept
IaaS offers infrastructure with greater guest-system control; PaaS abstracts part of the execution platform; SaaS provides an application as a service. Task allocation changes, but customers still make data and access decisions. Public cloud does not imply publicly accessible data: location and delivery model are not permissions.
Apply and decide
Hybrid architecture combines environments and needs coherent identity, connectivity, observability, and operations. Define intended benefits before choosing a model. Variable consumption may help with irregular demand, but an always-running application still generates costs. Ability to scale does not demonstrate that the configuration already scales correctly.
Workplace application
In the exercise, compare a legacy application requiring guest-system control with one adaptable to a managed platform. Record which tasks move to the provider and who manages the rest. Do not interpret public cloud as public data access. If the design is hybrid, include local dependencies in availability objectives and incident communication. A model choice should explain concrete benefits, constraints, and responsibilities.
An application with specific operating-system dependencies may need IaaS; another may benefit from a managed platform. The decision depends on compatibility and responsibilities.
Common pitfalls
Confusing service model with absence of customer responsibilities.
Related topics: Resource organization and resilience · Compute and connectivity
Choose the model based on required control and the work you want to manage.
Reference: Shared responsibility in Azure · AZ-900 skills measured July 20, 2026