Carbine and riffle are two different kinds of guns that are similar in appearance, but definitely different in their functionality. One of the first observable differences between carbine and rifle, probably, is their length. The carbine is of a shorter barrel and also found to be lighter than riffle. This makes it seem easier to handle, and many officers choose to handle it during a skirmish.
Due to the fact that the riffle is longer, more time is taken for the expanding air to produce projectile. This, making even the handler to feel more power whenever a shot is made from it. The bullet that comes out of the rifle actually becomes more stable, thus leading to better accuracy.
Another advantage here is that the bullet is less affected by external factors. The case is not so when it comes to the bullet shot from a carbine. The bullet can be more affected by external factors, thus altering the accuracy of the bullet. However, they both depend on how much the handler can handle it well.