I had to get to the practice tests to realize that Cosmos DB is actually a noSQL database. There was no mention of this in the entire lesson. They missed mentioning a significant fact.
For exam prep I would recommend also to check more extensive course from Linux Academy called "Microsoft Azure Fundamentals – AZ-900 Exam Prep (LA)". In this course under 6.5 chapter it is mentioned that Azure Cosmos DB is globally distributed, multi-model NoSQL database service.
There is also a cool summary called "The Book of Basics". The same info about Cosmos DB you can be found under 2.2.4 section.
Book can be downloaded from https://interactive.linuxacademy.com/diagrams/azurebookofbasics1.html