I believe windsucking is where horses bite stable doors (for example) and take big sucks of air in. Cribbing is biting things e.g stable doors!! could be wrong.
You can change the environment your horse lives in to try and stop the vices, ie if they live inside 24/7 they may reduce the vice if they had some turnout as stress can be one reson a horse develops vices in order to cope with their living situation.
The medical dictionaries will tell you that wind sucking is usually associated with crib biting, whereby the horse will grasp the edge of something (ie stable door), and pressing down on it, raise the floor of the mouth, and force the soft palate open and swallowing air.
The horse does not need to grasp to anything to do this, however, and will arch its neck, and suck in air.
There is quite alot of info on the internet which is very useful.