"Snake bite" or rim pinch: two parallel slits, caused by under-inflated tires or an impact on the rim (usually a pothole); the tire has compressed and squeezed the tube against the rim.

Blowout: a large hole like a starburst; usually caused by riding over a sharp object

Small pierce or hole: sometimes a staple, or other small, sharp object; sometimes caused by a spoke protruding through the nipple on the inside of the rim (be careful after tightening spokes)

Tear at valve stem: these cannot be repaired; caused by an improperly inserted valve - make sure the valve protrudes at a 90° angle to the rim