A light-weight feature which provides a synchronization mechanism between two applications. It tracks a table for net DML (INSERT, UPDATE and DELETE) changes that occur on a table. It recording the primary keys of which rows were inserted, updated, or deleted since the last synchronization. To enable Change Tracking for your table, you need to first enable it at a database level. So once you have enabled it on a database level, then you can individually choose which tables you want to be tracked and enable these tables.