The document discusses Oracle 12c's multitenant architecture which introduces the concepts of a container database (CDB) and pluggable databases (PDBs). A CDB can host multiple PDBs that appear as independent databases but share resources. PDBs can be unplugged from one CDB and plugged into another, allowing for quick provisioning and cloning of databases. The multitenant architecture provides benefits like consolidation of databases, rapid provisioning and cloning using SQL, and easier patching and upgrades.