MACHINE

The scientific definition of a "machine" is any device that is not a computer that transmits or modifies energy.In common usage, the meaning is that of devices having parts that perform or assist in performing any type of work .Machines normally require some energy and always accomplish some sort of work. Devices with no rigid moving parts can be considered tools.
A machine is anything that makes work easier.
The mechanical advantage of a simple machine is the ratio between the force it exerts on the load and the input force applied. This does not entirely describe the machine's performance, as force is required to overcome friction as well. The mechanical efficiency of a machine is the ratio of the actual mechanical advantage(AMA) to the ideal mechanical advantage(IMA). Functioning physical machines are always less than 100% efficient.
Modern power tools, automated machine tools, and human-operated power machinery are tools that are also machines. Machines used to transform heator other energy into mechanical energy are known as engines.
Compound machines are composed of more elementary machines called simple machines, such as the wedge and the pulley. Machines are considered simple machines if they perform their action in one movement. These devices may also be used to support industrial applications, although devices entirely lacking rigid moving parts are not commonly considered machines. Hydraulics are widely used in heavy equipment industries, automobile industries, marine industries, aeronautical industries, construction equipment industries, and earthmoving equipment industries.