Here is a simple comparison:
- this is a Google real time database
- without the aide of extensions or additional coding, Firebase Realtime Database only stores text files
- data is stored on Google's servers
- controls are similar to a CloudDB
- Costs: heavy use databases will have a charge See https://firebase.google.com/pricing; small usage is free.
- 🔥 Firebase Database and Storage: with the Web Component - Secure Rules
- still an 'Experimental' control. Google depricated the code MIT uses to access the database. MIT no longer updates the control since if Google changes the way linking works, the Experimental control will no longer work.
- Extensions provide enhancement.
- this is a Redis real time database
- it can store small png/jpeg files within the database and text
- data is stored (for non commercial Projects) on MITs server using default settings; can be stored on your own server using Redis
- controls are similar to a FirebaseDB
- Costs: free on MIT default server for non-commercial. Redis software is 'free', the cost on your own server is it's operating costs or the cost to have the database hosted on Redis' servers.
- MIT supports the CloudDB control which uses a Redis database.
Of course, there are other differences. Please read the documentation to see which is suitable for your application.