Microsoft Azure offers many services and resource offerings. For example, you can use the Azure Virtual Machines compute services to build a network of virtual servers to host an application, database, or custom solution, which would be an IaaS based offering.
Other services can be categorized as PaaS because you can use them without maintaining the underlying operating systems. For example, when you run a website in Azure Web Apps, or a SQL database in Azure SQL Databases it is not necessary to ensure that you are using the latest version of Internet Information Services (IIS) or SQL and have the latest patches and updates installed, as this is the responsibility of the Microsoft Azure platform.
Microsoft Azure is Microsoft’s public cloud offering that enables individuals and organizations to create, deploy, and operate cloud-based applications and infrastructure services. The Microsoft Azure public cloud platform offers IaaS, PaaS, and SaaS services to organizations worldwide.
An example of a SaaS service on Microsoft Azure would be Operations Management Suite, which is set up and accessed via Operational Insights services. Here, you just set up your management tools and connect into the services you wish to manage all through Microsoft Azure, so no local infrastructure is required or needed to be managed. The Microsoft Azure platform is responsible for all of that and provides direct access to the Management software. Microsoft Azure provides lots of services which fall into IaaS, PaaS or SaaS contexts and these services are constantly being added to and evolving.