Amazon RDS (Relational Database Service) is a cloud-based service that simplifies the setup, operation, and scaling of relational databases. It supports various database engines, including MySQL, PostgreSQL, Oracle, and SQL Server, allowing users to choose the one that best fits their needs. With Amazon RDS, users can easily manage backups, patching, and replication, which helps ensure high availability and durability. The service is designed to handle tasks like database provisioning and maintenance, enabling developers to focus on building applications rather than managing infrastructure. Amazon RDS also offers features like automated backups, monitoring, and scaling, making it a popular choice for businesses looking to deploy databases in the cloud efficiently.