you can enter session name you like.
the ID of the record that is inserted will be saved in a session of the name you specify, this can be used if you are doing an insert to two diferant tables to insert related information
lets say for example you are inserting to an orders and orders details table at the same time.
you would want to relate the order to the order details.
on the insert that saves the order, you could save the ID if the order to a session named orderID
then in the insert that saves the order details, use that session in the detailsOrderId column to relate the 2 records.