INSTEAD OF: Cause the trigger to fire instead of executing the triggering event or action. It prevents unnecessary changes to be made.

Example: Causes the trigger to fire instead of the update (action)

CREATE TRIGGER Employee_update ON Employee INSTEAD OF UPDATE AS { TRIGGER Definition }

AFTER: execute following the triggering action, such as an insert, update, or delete. These triggers are fired a little late in the process.

Example: Causes the trigger to fire instead of the update (action)

CREATE TRIGGER Employee_update ON Employee AFTER UPDATE AS { TRIGGER Definition }