title: Algorithm to check if two boxes overlap
body: <p>I have understood the algorithm in case of rectangles but I am confused with the boxes with x, y, z and height as value given. The conditions for not overlapping are
  1) Box A above Box B
  2) Box A below Box B
  3) Box A left of Box B
  4) Box A right of Box B</p>
  
  <p>Am I correct? Please guide some missing points.</p>