Door frames are also called jambs or casings. There are many types of door frames and all are made according to the shape of the door.
Every arched door is framed by an arched frame.
These types of doors are used for closets. They have runners along the top and bottom. These runners allow the door to slide open. They are frames with moldings that are squared in the spot where moldings meet or have mitered corners for smooth finishes. The molding can then be painted to match any color you want.