PaaS offers platform services, such as Web Apps, and cloud services such as SQL Server Services, Azure App Services, and so on. Whereas IaaS is all about containers and virtual machines, and anything installed inside that VM has to be managed manually by the user, PaaS offers cloud services where all the services are managed by the cloud provider. For example, if we need to host our database server on the cloud, one option is to take a VM and install the SQL Server on that VM itself. Using this model, the management of the SQL Server or the setting up of load balancing and failover has to be done by the user. But if we go with the SQL Server cloud service, which is platform as a service, it does all the load balancing, failover is done automatically, and we just need to care about our application databases and SQL objects. There are some constraints when working with the PaaS model, as it only supports a minimal set of versions of the tools or platforms services, and it totally depends on the business requirement, where the architect can decide to choose between IaaS and PaaS. Some examples of PaaS in Azure are App Services and SQL Azure.