Some people don't know the difference between airsoft and paintball guns, but there is indeed a lot of difference between the two.
Airsoft guns are usually close to exact of replicas of real guns such as desert eagles, colts, Ak-47s, and so on.
Meanwhile, paintball guns are big and weighty metallic objects that don't resemble real guns.
Both guns use different bullets as well.
Airsofts use BBs or tiny round balls as bullets.
These are much cheaper than the paintballs which the other kind of gun uses.
Paintballs also break more easily.
Thus, a clear path is needed for the shooter to hit his intended target.
These bullets travel slower as well, so it is actually possible to dodge them.
BBs, on the other hand, travel much faster.
They are almost impossible to see and avoid.
They are also less likely to fall apart and jam your gun as well.
As you can see, you will have to invest more money if you want to get into paintball than if you get into airsoft.
However, the comparison will probably end with cost.
There is no such thing as competitions wherein competitors can use both kinds of guns.
You have to use one or the other.
Thus, your choice of gun will ultimately depend of what you want to do.
  If you have the money and you want to look cool with your metallic paintball shooter then you should go right ahead with buying one.
But if you want to experience the feeling of using real guns while battling it out with others, then you should stick with buying airsoft guns.
So, have you decided yet? Then you should go buy the gun you want right now!