Station Interface/Commerce/Commodities
The Commodities subsection of the Commerce section of the Station Interface has itself two sub-tabs: the buy tab and the sell tab.
Buy
This tab allows the user to buy trade goods. The left pane is a list of all goods available at the current station. Trade goods that are locally produced will be indicated as such, and are generally the best items to buy and resell elsewhere. If you select a trade good in the left pane, a description of it will appear in the right panel. On the bottom of this screen are buttons to select the quantity of items to purchase, and to actually make the purchase.
Sell
This tab provides the user an interface to sell trade goods, both those on his ship and those stored in the station. The left pane displays all trade goods available for the user to sell, and the right panel displays a description of the selected item. Again, on the bottom of this screen are buttons to select the quantity of items to purchase, and to actually make the purchase.