When adding a contact or a company you can add notes that only your employees will see.
When you add a customer order the notes will be displayed. See Viewing notes when adding an order.
This feature is available on all plans and all editions.
Once you have set up your departments you can add department notes to a contact and a company. Department notes are used so you can give special instructions to your kitchen that only the relevant department will see. Department notes are displayed on the production log and they will appear every time that customer places an order.
This feature is available on the max plan and all editions.