As far as my knowledge goes, I hope to explain what these difference them.
In my HeadQuarter I can place an item and that goes in the list definitely. Building a trading dock in another sector, or even an Equipmentdock, these items can be stored there as well. (Have not tried all)
This gives the specific item the one way to the station option: No buying or selling. Does NOT auto refuel e-cells for docking ships. Can NOT import or export these goods with trade commands (Trade Distribution/Fetch Goods etc).
This gives the specific item the option for other factions to buy it. Leave a minimum if needed for building! (goes for others too except resource)
This gives the specific item the use-only-for-station option. Buy only. Does NOT auto refuel e-cells for docking ships. Can import these goods with trade commands, but not export.
This gives the specific item the trade option, every other faction can buy or sell it to you/from you. Can auto refill e-cells. Buy or Sell.
If, in all my wisdom, I have made a mistake, please help to improve and alter the text. I used it often wrong, and so I hope that with your (the community) help I eventually can make it into a helpfull page where starters can pull knowledge from.