A few pieces of information:
The vertical members of the frame are called stiles while the horizontal members are known as rails. A basic frame and panel item consists of a top rail, a bottom rail, two stiles, and a panel. This is a common method of constructing cabinet doors and these are often referred to as a five piece door.
This is a standard cabinet practice, to provide strength to the door, now the caveat, it doesn't matter the orientation of the door, the hinge always attaches to the longer stile. Hope this helps.
2015 Wildwood 27RKSS
2015 Silverado 2500HD Duramax