i have a dumb question

just bought a refurbished desktop, OptiPlex 380 if anyone had or had this model, one question:  is it a stand up tower? or is it suppose to lay on one side horizontally?  it has what seems to be foot pads on both the narrow bottom, and also on one side.  Also the dvd drive stands vertically if it's a tower.  when I bought it the photo showed it as a tower, but I'm just not sure