A synonym is a database object, which is used as an alias for a table, view or sequence.
Private synonym is available to the particular user who creates.
Public synonym is created by DBA which is available to all the users.
Hide the name and owner of the object.
Provides location transparency for remote objects of a distributed database.
Syntax for Private Synonym
Create Synonym sysnonym_name for table_name;
Syntax for Public Synonym
Create Synonym Public sysnonym_name for table_name;
CREATE AND DROP
SQL> create synonym s1 for emp;
SQL> create public synonym s2 for emp;
SQL> drop synonym s1;