End-grain cutting boards offer one advantage over regular, long grain boards. The latter will become scarred with use, as knives will cut the fibers of the wood. With end-grain boards, the ends of the fibers make up the cutting surface. When a knife blade cuts across the surface, the knife edge moves between the fibers, which means that there is a lot less scarring. I have one of the boards below (the first one) in my kitchen, and it has been used very heavily. The surface shows minimal scarring. End-grain boards will also be easier on knives, as they do not cut the fibers but sink between them.