Triggers are database object. Basically these are special type of stored procedure that are automatically fired/executed when a DDL or DML command statement related with the trigger is executed. Triggers are used to assess/evaluate data before or after data modification using DDL and DML statements
trigger is a special kind of storedprocedure which will invoke immediately dml operations like insert update delete.. there are two type of triggers 1)ddl triggers 2)dml triggers