Inventory ,Cost management which one does Transfer to GL?

Hi,

Inventory has its transactions(material trx etc),and there are inventory periods, however I don't see the Transfer to GL program in inventory application.

Costing too has its own transactions,but when I open the cost periods,it goes to inventory accounting periods(so no costing periods per se?), but then there is a Transfer to GL program.

So I want some clarity on if there are two different accounting periods in Inventory and Costing and whether the transactions flow from both Inventory and Costing to GL separately as part of the regular month end process. 

Can someone provide some clarity on the above question, appreciate it.