Triggers define the code that runs in response to specific events. There are three types of triggers available in SQL Server, as follows:
DML triggers fire when data modification occurs. You can use DML triggers in cases where you need to enforce specific business rules during data modifications and the system does not have a dedicated data access tier implemented. You can think about audit-trail functional, which captures who changed the data in the table, as an example. When a system has multiple applications working with the database directly, an audit-trail implementation based on triggers ...