A hosted environment that allows you to write and run programs without having to manage the underlying operating system is an example of which cloud model?

A hosted service that allows you to develop upon it is an example of the platform-as-a-service (PaaS) model. The cloud provider is responsible for the delivery of APIs that developers can use to create programs. An example of infrastructure-as-a-service (IaaS) is Amazon Web Services (AWS), where a VM can be started up with virtual network services with only a credit card and you are billed periodically. An example of software-as-a-service (SaaS) is your email provider or a customer relation management (CRM) company such as Salesforce. An example of backup-as-a-service is Microsoft Azure cloud backup or Google Drive, just to name a couple.