Amazon RDS vs PostgreSQL

Amazon Relational Database Service (RDS) is a managed database service from AWS that supports MySQL, PostgreSQL, MariaDB, Oracle, SQL Server, and Db2 engines. It automates hardware provisioning, database setup, patching, and backups with options for Multi-AZ deployments and read replicas.

PostgreSQL is Open-source relational database known for extensibility, SQL compliance, and a rich ecosystem of extensions.. It is available under a free model. This tool falls under the databases category.