Synonym : It is an unqualified alternative name for a table or view.
VIEW : It is a virtual table made up of data from base tables and other views, but not stored separately.
ALIAS : An alias is an alternative to a synonym, designed for a distributed environment to avoid having to use the location qualifier of a table or view. The alias is not dropped when the table is dropped.
Alias and synanyms are alternate names for DB2 objects with the following differences.
Synonym:
1. this is the local object only user has to create and access it.
2.used in local environment.
3.when base table is dropped automatically synonyms are dropped.
4.SYSADM authority is not needed.
Alias:
1. this is the global object.
2.used in distributed environment.
3.when base table is dropped aliases not dropped.
4.SYSADM authority is needed to create this or CREATEALIAS previlege is needed.