This question continues to come up, as more workloads and applications move to the Azure cloud, every solution architect needs to understand what options are available with regards to Azure SQL, and what is the difference between SQL IaaS, PaaS (Single DB and Managed Instance)…
Of course, there are many moving parts when it comes to make the right decision.. Should I lift and shift and rehost SQL as a VM? Should I migrate to a PaaS offering today or can I wait it out? Etc., etc.
Over the course the last 12-14 months, I have been presenting on how to go about migrating your on-premises SQL to Azure and the possible paths to get there. Below is an image I use quite often as it shows you want features and capabilities exist (or do not exist) when you decided to select, SQL Single DB PaaS, for example.
I hope this helps. For an updated link, please see Microsoft’s page here where you can view all the possible SQL deployment options: HERE.
Please note, this image is not mine as it was found on the web, courtesy of Ivan Kosyakov.