It is any device that provides input to acomputer.
"It is a computer peripheral that the user can use to enterdata into a computer"
They are usually smaller in size than output devices and havephysical attributes that emphasize on comfort and easeofuse.Input devices typically handle data input through buttons, lens ormicrophone.
An input device allows users the opportunity tocommunicate and feed instructions and data tocomputers for processing, display, storage and/ortransmission.