Excellent book packed with info, tricks, highly illustrated--will save you time/money.
A crampon is a device used for ice climbing or mountaineering over ice or steep snow fields. They are made to fit special ice climbing boots or welted mountaineering boots for attaching. Crampons can be made of a steel or aluminum frame with 12 to 14 points designed to stick into the ice or packed snow. The points are angled in such a way to give the best grip on the ice. For ice climbing, the front row of points angle slightly downward. The next row are angled slightly forward, toward the toe. This provides the climber the best angles for front pointing. However, if the use of the crampons is for mountaineering, the points are straight down. This provides better traction for traversing packed snow and the type of terrain encountered in mountaineering. Crampons designed for mountaineering, snow and glacier are not good for ice climbing for this reason.
This is a situation that occurs when snow is packed and freezes at the toe or around the points of the crampon. It is a problem because it prevents the crampon's points from sticking into the ice far enough to get a good grip. The ice climber must use the ice tool to knock off the loose snow has he climbs to prevent accumulation. Many crampons have shaped slabs made of flexible plastic called anti-balling plates. The plastic is a hydrophobic material that prevents snow and ice from sticking.