Here is where you enter the compartment for this pack.
As you can see, the Pack name is already assigned because you inserted this new compartment by clicking on the pack. The compartment number is already assigned as well. It is advised to leave these 2 fields alone.
Enter the compartment name and the location of this compartment on your pack.
You may go ahead and enter the actual items from this screen as well, but if you are just learning, please just press enter or click OK to save this compartment record.