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