I'am trying to model a tank wheelchair, I have made a curve for tank treads but when I make array of cubes it is not following the curve. What should I do so that my cubes not only follow the curve but also I could be able to move the cubes along curve to simulate tank tracks?
Your cube must have the same position as the curve (select the curve, hit Shift+S and Place 3D cursor to curve's origin, then select the cube and again Shift+S to move Selection to 3D cursor). Also, you must apply transformations on the cube so it can properly fit the curve (Ctrl+A). I have updated and attached your file so you can look at it.