The banks allow you to preset your camera for four shooting and four custom banks. While they can be used in any combination (4x4=16), most folks just keep them synchronized.
Check out the pinned thread with the spreadsheet for examples on how you might set them up.
Feel free to ask questions.
---------+---------+---------+---------+ Joseph K Seattle, WA, USA
Nikonians®, NikoScope® and NikoniansAcademy™ are trademarks owned by Nikonians.org.
Nikon®, Nikonos® and Nikkor® are registered trademarks of Nikon Corporation.