A jigsaw is a saw which uses a reciprocating blade to cut irregular curves, such as stenciled designs, in wood, metal, or other materials.
A power jigsaw
Battery-powered jigsaw
T-shank blades
Image: Jigsaw Accu Master
A saw is a tool consisting of a tough blade, wire, or chain with a hard toothed edge used to cut through material. Various terms are used to describe toothed and abrasive saws.
Roman sawblades from Vindonissa approx. 3rd to 5th century AD
Bronze-age saw blade from Akrotiri, late Cycladic period c. 17th century BC
Saw grinding in Sheffield, 1860
Rip sawing c. 1425 with a frame or sash saw on trestles rather than over a saw pit