Hey, AVD is a platform service in Azure with its own mgmt tools in the Azure Portal / via PoSH... you can use something like Nerdio to close a lot of the gaps when comparing to Citrix (Studio/Director etc)... that said, you can use licensing to run Windows 10 multisession in Azure with Citrix / Citrix Cloud... but this is not 'AVD'... James K has a nice article here:
https://jkindon.com/citrix-cloud-and-avd-fluff/