In your store's Admin area, go to the Sales > Orders > Edit Order
These are used for storing some additional order details, such as payment results, and for adding notes to the order for customers to view. Some payment gateways also add notes for debugging.
In the Status & Comments area the store owner can change the status of an order, type a new comment to the customer to read when logged into their store account, and by checking the "Notify Customer" and "Append Comments" checkboxes the customer is notified and a new comment is added for tracking.
Notify Customer - If the customer is notified, they will receive an email in the format of the order confirmation email.
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