Jointers, also known as surface planers, are woodworking machines designed to flatten and smooth the faces of rough lumber and create straight edges on boards. They consist of a flat, rotating cutterhead and an infeed/outfeed table arrangement. Wood is passed over the infeed table and guided onto the rotating blades, which remove material to create a flat surface. Jointers are essential tools for achieving precision and accuracy in woodworking by ensuring that boards have smooth, even surfaces and straight edges. Woodworkers use jointers in combination with other tools, such as thickness planers, to prepare lumber for various woodworking projects.