INTERIOR AND EXTERIOR
Although there is nothing to keep you from building the grandest
exterior door and hanging it inside the house, there is every
reason not to use an interior door in an exterior opening. The
reason is that exterior doors are built to higher specifications,
with Choice wood, heavier sections, and higher hinges and locks;
they are fitted with various drips and rabbets to throw off the
water and hung so that they open inward.
The opening in which the door is fitted specifically, the side
of the opening.
The thin wood used to line the opening before fitting an interior
wood door; also called simply the lining.