The correct answer is PaaS provides a platform allowing customers to develop, run, and manage applications without the complexity of building and maintaining the infrastructure associated with developing and launching an app. This includes hardware as well as operating system management, which sets PaaS apart from other service models. SaaS delivers software directly to the user over the internet on a subscription basis, involving no developer control over the cloud infrastructure, and IaaS provides virtualized computing resources over the internet, where the user still has to manage operating systems, storage, and deployed applications.