A typewriter is a mechanical or electromechanical machine for typing characters. Typically, a typewriter has an array of keys, and each one causes a different single character to be produced on paper by striking an inked ribbon selectively against the paper with a type element. At the end of the nineteenth century, the term 'typewriter' was also applied to a person who used such a device. The QWERTY keyboard layout, developed for typewriters in the 1870s, remains the standard for computer keyboards. The origins of this layout remain in dispute.