The tables "INSERTED" and "DELETED" are called magic tables of the SQL Server. We can not see these tables in the data base. But we can access these tables from the "TRIGGER" They are called magic tables because like a magic you can't see it but they are actually there to be used inside triggers
Because these are not visible in information schema like, sys.tables and are visible only within the scope of a trigger.
In sql we hav two magic tables Inserted, deleted when we perform any operation of DML like insert, delete,update then these tables activate automatically .... we can not see these table but can use through trigger...