Firebase uses a NoSQL for it’s cloud-based databases
Like many NoSQL databases, Firebase’s Real-time database stores data as JSON objects
NoSQL databases don’t enforce strict data structure which results in much more flexibility than traditional SQL databases
Downsides: when dealing with “loosely structured” data, common use cases such as building out relationships (for example: a student has many courses, and courses contain many students) in your data can be non-intuitive and complex