synonym is an alternative name for objects such as tables views sequences stored procedures and other database objects. A synonym (synonym-name) is an alias for an object (such as a table). The object does not need to exist at the time of its creation. Synonyms can't be used in a drop and truncate statements. If this is tried it results in a ORA-00942: table or view does not exist.
Two types of synonyms in Oracle: Private Synonyms and Public Synonyms.