Amazon RDS (Relational Database Service) is a managed database service provided by Amazon Web Services (AWS). It simplifies the process of setting up, operating, and scaling a relational database in the cloud. RDS supports several popular relational database engines, including MySQL, PostgreSQL, Oracle Database, Microsoft SQL Server, MariaDB, and Amazon Aurora. With RDS, users can launch a database instance in minutes, automatically apply software patches and updates, take backups, and restore data from a snapshot. RDS also provides automated scaling capabilities to accommodate changes in database workload.