A software company needs a cloud-based environment that allows developers to write, test, and deploy applications without managing the underlying infrastructure. Which cloud service model is being used?

SaaS delivers software applications over the internet on a subscription basis, allowing users to access applications without installation. However, it does not provide the development tools required for writing and testing applications; instead, it focuses on delivering finished software solutions.

PaaS is specifically designed for developers, offering the necessary tools and services to create, test, and deploy applications in a managed cloud environment. This model abstracts the underlying infrastructure, enabling developers to concentrate solely on application development without worrying about server management.

IaaS provides virtualized computing resources over the internet, allowing users to manage their own operating systems, storage, and applications. While it offers flexibility and control, it requires users to handle the infrastructure management, which is contrary to the requirement of focusing solely on application development.