Computer hardware is the collection of physical elements that combine to form a computer system. Computer hardware is the physical parts or components of a computer. Some examples of hardware are monitor, keyboard, computer data storage, hard drive disk, mouse, sound card, etc. Hardware is a physical object that can be touched whereas software is untouchable. Software exists as ideas, applications, concepts and symbols. A combination of hardware and software forms a usable computing system.
Computing hardware evolved from machines that needed separate manual action to perform each operation, such as punched card machines and then evolved to stored-program computers. The history of stored-program computers relates the organization of the units to perform input and output, to store data and to operate as an integrated mechanism.
Before the development of the general-purpose computer, most calculations were done by humans. Mechanical tools to help humans with calculations were called calculating machines, now called calculators. Those people also used the machines, now called computers, to aid in calculations. The invention of the electronic amplifier has made calculating machines much faster than their mechanical or electromechanical predecessors.