Managed, highly available RDBMS with MySQL, PostgreSQL, and SQL Server.
Traditional RDBMS, enterprise/business applications, web applications.
Horizontally scalable, globally/regionally distributed, highly available, strongly consistent RDBMS.
Mission critical applications that requires 99.999% SLA. Regionally or globally available applications that needs fast data access. Large data sizes that no longer fit in traditional RDBMS.
Managed NoSQL Document-oriented database.
Applications with data structure that's fast changing, or document oriented.