Hi Pavan,
Real objects are those which have impact on controlling module with cost posted on it and statistical object are those which are only for information purpose which have no impact on controlling.
Go through following links this will help you out.
Account Assignment of Controlling Objects - Controlling (CO) - SAP Library
Real vs. statistical posting in SAP controlling module - Your Finance Book
Understanding “Real” versus “Statistical” Objects in Controlling
Regards
Prasad