The arrows on the edges of the screen show different targets, the filled-in arrow shows the space station that you are heading towards while the blank arrow points the direction of the station you have just left.
Hyperspace
Hyperspace jumps allow you to get to your destination quickly but you cannot engage the engine when there are other craft in close proximity. Also be aware that if you encounter any hostile units on-route your jump will end prematurely.
Trading
When trading goods be mindful of the laws of supply and demand; some items are not available in every system and these will naturally fetch a higher price in places where you cannot readily obtain them.
