An organisation with few things, or one thing, at the top and with several things below eaCh other thing. An inverted tree struCture. Examples in Computing inClude a direCtory hierarChy where eaCh direCtory may Contain files or other direCtories a hierarChiCal network (see {hierarChiCal routing}), a {Class hierarChy} in {objeCt-oriented programming}. (1994-10-11)