Bind Edge
Long Edge binding means the finished book will be portrait. Long edge binding is not
available on 8.5"x14" (Legal) and 11"x17" (Ledger) papers
Short Edge binding means the finished book will be landscape
So for example, assume you have a 5.5"x8.5" booklet. With long edge binding, the flat size of the booklet will be 8.5"x11" and the binding will occur on the 8.5" side. With short edge binding, the flat size of the booklet will be 5.5"x17" and the binding will occur on the 5.5" side