String trimmers, brush cutters, and edgers perform specialized lawn and landscaping cutting tasks where lawn mowers are too large or overpowered. String trimmers whirl a trimmer line to clip grass and cut down weeds along walkways and fences, around trees and flowerbeds, and near buildings and other barriers. Lawn edgers and bed redefiners remove overgrowth to leave a clean-cut border along yards and garden beds. Brush cutters deliver more cutting power than string trimmers to slice through dense undergrowth, thick weeds, and saplings.