A chainsaw (alternatively spelled chain saw) is a portable, mechanical saw which cuts with a set of teeth attached to a rotating chain that runs along a guide bar. It is used in activities such as tree felling, limbing, bucking, pruning, cutting firebreaks in wildland fire suppression and harvesting of firewood. Chainsaws with specially designed bar and chain combinations have been developed as tools for chainsaw art and chainsaw mills. These specialized chainsaws are used for cutting concrete during construction developments. Chainsaws are sometimes used for cutting ice, for example, ice sculpture and winter swimming in Finland. Someone who uses a saw is a sawyer.