A large, open, living space, just waiting to be explored. Although I have newer X games, I often get back to this one, because it has it's unique and remarkable atmosphere that no other X game has. It's by far one of the deepest and games I've ever played and if you also love space and strategy games, there's a high chance you'll quickly get addicted into this one. If you want to try the X series, which is the best modern space simulator nowadays, don't care so much about the story (in case you don't care starting with a bit old X1) and don't want to spend many hours of learning from the community tutorials, start right here with X2. It has a nice ingame tutorial, unlike X3 games.
The trade-fight-build-think motto quite sums it up. The game itself consists of huge universe which is divided into sectors, between which you fly by gates or jump drive. At almost all sectors there are stations at which you can land and buy/sell wares on. A factory produces weapon components which a ray emitter factory need, and will buy energy or ore from you. AI-controlled freight ships fly between those stations, across the whole universe, and search for good trades. The more ammounts of some ware a station needs, the lower the price, and so it dynamically changes and creates a complex, working economy system, which the universe relies on. You attack a ship transporting energy to a station, the station won't receive what it needs in time, it won't be able to produce the required ammounts of products, and it's sales will go down. So all your actions have their consequences and the universe feels "living" because of this, as you see all those ships traveling around you, everywhere in the universe (you should have a decent processor for this btw).
You can also make money by fighting pirates, which fly around and randomly attack other ships. If you destroy their local station, you will significantly reduce the ammount of them, in the specified area. Or if you want, become one of them and smuggle space weed on your own risk.If you choose the trade route, you can build stations and create a huge, prosperating empire. Assign freight ships to them, give them commands to work autonomously, also the same to defense ships. Then you can afford those huge capital ships which you can fly by yourself, from the bridge. The commanding console system gives you a huge power if you learn how to use it, especially if you love automatisation and to see how money quickly flow into your account!
The story is in some parts a bit frustrating and hard. Newbies find it hard to even dock with a station without exploding, or to get any money. But keep in mind that this game needs a lot of time to learn, to fully enjoy it. If you're starting with only a light fighter you can usually only attack the same classes or only one-class higher from you (and not in formation) ships, if you're good enough. I recommend to start by fighting light pirates, trading wares between stations, and do many side missions. But the real fun starts when you build at least 10 factories and get yourself a nice corvette with turrets and go exploring on your own ;)