The acronym PaaS stands for Platform as a Service in cloud computing. It refers to a cloud service model that provides clients with a platform to develop, run, and manage applications without the complexity of building and maintaining the underlying infrastructure. PaaS offers tools and services designed to facilitate the entire application lifecycle, from development and testing to deployment and scaling. Developers can focus on coding, while PaaS handles system software, runtime, and other resources. Examples include services like Google App Engine and Heroku.