A power tool is an instrument that is actuated by an additional power source 
and mechanism other than the solely manual labor used in combination with hand tools. The most typical types of power tools use electric motors. Internal combustion engines and compressed air are also frequently used. Other power sources include steam engines, direct burning of fuels and propellants, such as for example in powder-actuated tools, or even natural power sources such as for example wind or moving water. Tools straight driven by pet power are not generally considered power equipment.
Power tools are used in industry, in structure, in the garden, for housework jobs such as cooking, cleaning, and around the house for purposes of driving (fasteners), drilling, trimming, shaping, sanding, grinding, routing, polishing, painting, heating and more.
Power tools are categorized as either stationary or portable, where portable means hand-held. Portable power equipment have apparent advantages in mobility. Stationary power equipment, however, often have advantages in speed and accuracy. A typical table saw, for example, not merely cuts faster than a regular hand saw, but the cuts are smoother, straighter, and more sq . than what’s normally achievable with a hand-held power saw. Some stationary power equipment can produce objects that cannot be manufactured in any other method. Lathes, for example, produce truly round items.
Stationary power tools for electric power tools metalworking are often called machine tools. The word machine tool isn’t usually applied to stationary power tools for woodworking, although such utilization is from time to time heard, and in some cases, such as drill presses and bench grinders, precisely the same device is utilized for both woodworking and metalworking.