New feature in 12c

1. Restore + recover individual tables from rman backup but prior  you can done from flashbackup/exp-imp/recover complete database to new location.

2. Auto conversion for cross-platform backup/restore

3. Automate the use of incremental backup to bring standby back in sync.

4. RAC- Real Transparant Failover Mechanism: both query and transaction are transparent but prior only query is transparent but ins/upd/del is not.
(Currently only for java connection pool or plain jdbc)

5. dataguard- global data services (no client reconfiguration in case of failover or switchover )

6. sql : Duplicate indexes can be created

7. Impdp can be done in NOLOGGING

8. Move datafiles online While read and write activity are going on

9. ‘container database’ Background processes, Memory allocation. Multiple ‘pluggable databases’ The union of Tables, views, procedures,all application objects, User definitions,Privileges