A saw is a tool with a toothed blade used for cutting materials. It is one of the oldest tools in human history. The modern saw is powered by electricity, gasoline, or a battery. It can cut wood, metal, masonry, and plastic. The saw is essential to construction. Without it, materials could not be sized to fit. The saw is a simple concept with many variations. Each variation is designed for a specific material and a specific cut.

Saws come in several types. A circular saw has a round blade and is used for straight cuts in wood and metal. A miter saw is a circular saw mounted on a pivoting arm, used for accurate crosscuts and angles. A table saw has a blade mounted in a table, used for ripping and crosscutting. A reciprocating saw, also called a Sawzall, has a back-and-forth blade, used for demolition and rough cuts. A jigsaw has a fine blade, used for curves and intricate cuts. A chainsaw is used for cutting trees and large timbers. A handsaw is a manual saw for small cuts. Each has its own purpose.

Saw safety is critical. The blade must be sharp. A dull blade binds and kicks back. The material must be supported. The user must wear safety glasses and hearing protection. The blade guard must be in place. The power cord must be intact. The user must not reach across the blade. Kickback is the most common accident. It happens when the blade binds and the saw jumps back toward the user. The user must stand to the side of the blade. The saw is a powerful tool. It demands respect. It can cut wood. It can cut flesh. The difference is attention.