How to create Database Link

CREATE PUBLIC DATABASE LINK ..

CONNECT TO ..

IDENTIFIED BY ..

USING '(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = )(PORT = )) (CONNECT_DATA = (SID = )))';


USING '(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = )(PORT = )) (CONNECT_DATA = (SERVICE_NAME = )))';