Azure has quotas that can limit things such as the number of VM's you can have running per region. It won't provision more vm's than you have in your quota. This helps you, for example, avoid automatically provisioning more vm's than you expect. These quotas can be edited manually or via API.

https://docs.microsoft.com/en-us/azure/azure-resource-manage...

https://docs.microsoft.com/en-us/azure/azure-resource-manage...