Explain briefly what is Azure Cloud Service.

Azure Cloud Service is a Platform as a Service (PaaS) cloud computing model that is hosted on Virtual Machines (VMs). Azure assists applications that need high levels of scalability, stability, and availability while yet operating at a low cost. By setting up a cloud service instance, Azure cloud services are used to deploy multi-tier web-based applications on Azure.

There exist two types of Azure roles which differ in the way they are hosted on the VMs:

• Web Role: host and deploy the app over Internet Information Services (IIS) automatically,
• Worker Role: execute the app without using IIS.