Amazon's own RDS engine. MySQL and PostgreSQL compatible.
5x better performance than MySQL and 3x better than PostgreSQL, for a much lower price point.
Start with 10gb, scales in 10gb increments up to 128tb. Compute resources can scale massively too.
2 copies of your data are contained in each AZ, with a nimum of 3 AZs (for a total of 6 copeis).
3 different types of replicas available:
Automated backups are always enabled. You can also take snapshots, which can be shared with AWS accounts.
Aurora Serverless also exists, that automatically starts up, shuts down, and scales up/down depending on your application's needs. Good for infrequent or unpredictable workloads.