IaaS (Infrastructure as a Service) and PaaS (Platform as a Service) are two cloud computing models that serve distinct purposes, differing primarily in the level of control and responsibility they place on users. IaaS provides virtualized computing resources—like virtual machines, storage, and networks—over the internet, allowing users to manage the operating systems, middleware, and applications running on those resources. PaaS, on the other hand, offers a complete development and deployment environment, abstracting away the underlying infrastructure so developers can focus solely on building and deploying applications.
The key distinction lies in the scope of management. With IaaS, such as AWS EC2, Azure Virtual Machines, or Google Compute Engine, developers configure and maintain virtual servers, install software, and handle scaling. For example, if you deploy a web app using IaaS, you’re responsible for setting up the server OS, installing a web server like Nginx, and managing security patches. In contrast, PaaS solutions like Heroku, Google App Engine, or AWS Elastic Beanstalk handle infrastructure management automatically. If you deploy the same app on PaaS, the platform manages server provisioning, runtime environments, and scaling. You only provide the application code and define configuration settings (e.g., environment variables), reducing operational overhead.
Use cases further highlight the difference. IaaS is ideal for scenarios requiring granular control, such as running legacy systems, custom databases, or applications with specific compliance needs. For instance, a company migrating an on-premises ERP system to the cloud might choose IaaS to replicate their existing infrastructure setup. PaaS suits developers prioritizing speed and simplicity, such as building microservices, APIs, or web apps where infrastructure details are irrelevant. A startup developing a new SaaS product might use PaaS to avoid infrastructure management and accelerate time-to-market. Choosing between them depends on whether the team needs flexibility (IaaS) or wants to offload infrastructure tasks (PaaS).