The purpose of a bike rack is to simply keep a bicycle upright and steady in position and is perfect for use in a wide variety of environments including around the house, in a bike shop or for staff access. Of course, it is possible to lock a bike to a bicycle stand, but because of its small size a bike stand is generally meant for keeping your bicycle upright, not securing it from theft.
For owners or managers of public facilities who want to allow access to large numbers of cyclists, parking rails are generally considered the more secure option. The main difference is that a parking rail is much larger than a stand. A bike stand is wide enough to accommodate your bike