Azure Cloud Services is an example of a platform as a service (PaaS).
Like Azure App Service, this technology is designed to support applications that are scalable, reliable, and inexpensive to operate. In the same way that App Service is hosted on virtual machines (VMs), so too is Azure Cloud Services.
However, you have more control over the VMs. You can install your own software on VMs that use Azure Cloud Services, and you can access them remotely.
In Azure Cloud Services, you’ll get many of the features of App Service, like support for multiple deployment, automatic OS upgrades, and seamless platform switching. But in addition, you’ll also get Remote Desktop (RDP) access to servers, custom MSI installations, the ability to define and execute start-up tasks, and to listen to Event Tracing for Windows (ETW) events.
Hope this helps!