A chainsaw (or chain saw) is a portable gasoline-, that cuts with a set of teeth attached to a rotating driven along a guide bar. It is used in activities such as tree , , , , cutting in , and harvesting of . Chainsaws with specially designed bar-and-chain combinations have been developed as tools for use in and . Specialized chainsaws are used for cutting concrete during construction developments. Chainsaws are sometimes used for cutting ice; for example, and in Finland.