The image above shows a 'Trader' building.
A 'Ship Trader' building has a repair symbol instead of a shopping cart above it.

Wares are items that are too large to fit into a player's inventory and are often used for trading between stations in large quantities.

Inventory Items are small items which a player can pick up and must be sold to a Trader in a station. Every station has a trader and you must exit from your ship and walk to a building inside the station's dock.

Wares are easy to trade and use the standard 'Trade' option from the ship menu.

NOTE: AI Ship pilots can AutoTrade if they have an overall 'Star Rating' of at least 3 stars. (Fire pilot and get a new one from upgrade ship until you have one)

AutoTrading gives you the difference of trading to all of the stations that you have been near. Trades will usually only give between 100 to 5000 credits depending on the ware and cargohold size.

To AI AutoTrade, click the ship that you want to trade with and use 'Information'. On the top left there is a symbol for Behavior next to the ship information icon. Under Default Behavior, set to AutoTrade in the dropdown and zoom out with the Trade Map filter on. Pick the best trades by selecting each ware and comparing global prices. Select a few good wares that will turn a profit and send the ship on it's way.