Amazon Relational Database Service (Amazon RDS) for Oracle now supports the Oracle Multitenant configuration on Oracle Database versions 19c and 21c running Oracle Enterprise Edition or Standard Edition 2. With this release, the Amazon RDS for Oracle DB instance can operate as a multitenant container database (CDB) hosting one or more pluggable databases (PDBs). A PDB is a set of schemas, schema objects, and non-schema objects that logically appears to a client as a non-CDB.
Source:: Amazon AWS