One perception that some people can have, looking into the scene from outside, is that people are either tops or bottoms. Either you like to dominate, or you like to be dominated. And sometimes novices become confused, because they’re excited by _both_ possibilities.
The facts are, everyone is different, and everyone has their own preferences. I personally greatly enjoy topping my girlfriend, and also greatly enjoy submitting to her. Some people _are_ tops in every play situation, just as some are bottoms in every play situation–but I know people who top men but bottom to women, people who sometimes switch roles multiple times within one date, and every other spectrum of possibility!
People who top are called “tops”, people who bottom are called “bottoms”, and people who switch back and forth between topping and bottoming are called “switches”. A switch can be a top in one scene and a bottom in another. Some people switch back and forth often; others switch only between scenes, but retain one role throughout any individual scene; others switch only very seldom with people that they trust very deeply; and still others never switch at all.
If you do switch, and you’re not sure which role you want, you can play with that question in itself. Whole scenes can revolve around the “who’s on top?” question. Maybe you can have a wrestling match, and the person who gets pinned first will wind up being tied up. Maybe you can set a timer, and when the timer dings, it’s time to switch positions! There are as many possibilities as your imagination can dream of!
Then again, maybe only one side of the balance holds any appeal for you, and in that case, you’ll want to play with folks who have little desire for _your_ side… it takes all kinds, and all kinds are out there.
It is also the case that there is no necessary relation between whether someone is dominant or submissive in everyday life and whether they are a top or a bottom. Some of the most domineering executives secretly love being abased and abused… it’s a chance for them to lose control, to give up responsibility. And some of the most quiet, meek, shy-looking people you’ve ever seen turn into demonic geniuses of pain and pleasure when given someone to play with.
It’s not at all unheard of for someone who’s done only one thing (for example, bottoming) to one day start feeling the urge to top, or vice versa. People change, preferences change, it’s nothing unusual. This, though, leads into the next question….