Oracle: Differnce between to_date('01-JAN-00','DD-MON-RR') and to_date('01-JAN-1900','DD-MON-YYYY')

Difference between to_date('01-JAN-00','DD-MON-RR') and to_date('01-JAN-1900','DD-MON-YYYY')

Result of to_date('01-JAN-00','DD-MON-RR') will be '01-JAN-2000'  where 'RR' refers to current century
Result of to_date('01-JAN-1900','DD-MON-YYYY') will be '01-JAN-1900'.

Note: By default, if you do a 'Save As' with Insert , the default format will be in 'RR'.