When a customer order an item online, or when you create an order for a customer internally, the order goes into the customer order history. To view a specific customer order, access/edit their account and scroll down to the orders section. The "Orders" option allows you to view ALL orders regardless of who they belong to:

Click the pencil icon to edit the order information. Click the magnifying glass icon to view the order in its printable format. Customers can also login to their account and get a list of all their orders. They can also print a copy of their orders.