A model where the provider manages hardware, OS, and middleware. The customer only deploys and manages their applications and data. Ideal for developers who want to focus on code without managing infrastructure.
In AZ-900: Azure App Service, Azure SQL Database. In CLF-C02: AWS Elastic Beanstalk, AWS RDS. Critical difference from IaaS: with PaaS you never touch the OS. Versus SaaS: with PaaS you still control your app code.
PaaS (Platform as a Service) is a concept that can show up on the exam. Check the full guide to see it in context.