For me, the most important difference is that a SQL "Database" is actually an incredibly powerful application server, with a built in compiler for a data proces

For me, the most important difference is that a SQL "Database" is actually an incredibly powerful application server, with a built in compiler for a data processing language, and many years of development on access strategies, whereas a NoSQL database is just a level above an http server with an index that scales really well. That's a bit of an exaggeration, but I find it helps new teams understand the big picture. In a microservice environment, I encourage my teams to think of their SQL database server as a microservice, not a persistence store.