For each order row you can add many different values like: 

- number of units 

- price per unit

- cost per unit

- discount etc.

Each column can be hidden if you believe they are not valuable to use. After a order row column has been hidden it stays hidden until you click the Unhide all button.

Sales value

The value of the Opportunity is the summary of the value of all connected order rows.

Revenue values

Each order row can have a start and end delivery date. The total value of the order row will be divided into the corresponding time period between the start and end date and be classified as revenue.