Cordless circular saws are battery-operated so they don't require access to a wired power source. Circular saws have a round blade that spins on an arbor to make rough rip, cross, and beveled cuts in wood and metal. Metal-cutting saws have a lower RPM and higher torque than general purpose circular saws. General purpose saws are most often used for cutting wood, but can be used for cutting other materials depending on the blade used for cutting.