Platform as a Service (PaaS) is a cloud computing model that provides developers with a platform to build, deploy, and manage applications without worrying about the underlying infrastructure. It offers tools and services such as databases, development frameworks, and middleware, allowing developers to focus on writing code and creating features. PaaS solutions are typically hosted in the cloud, enabling easy access and collaboration among teams. Popular examples of PaaS include Google App Engine, Microsoft Azure, and Heroku. These platforms streamline the development process, reduce costs, and enhance scalability, making it easier for businesses to innovate and respond to market demands.