Braided area rugs are constructed in several different ways, including tape, tubular, and flat. Tape braided rugs are constructed by weaving the surface finish yarns into flat "tapes" which are then folded and braided together in a traditioanl braid. Tubular braided rugs are constructed by wrapping the surface finish yarns around a single core--usually a waste yarn. Flat braided rugs are constructed by braiding the surface finish yarns around two center strands of yarn. The finish braids are then sewn into a variety of shapes, including ovals, rectangles, octagons, and squares.
As far as the different types of constructions go, flat braided rugs tend to be the most durable; however the quality of any braided rug depends on the materials used and the quality of the braiding and stitching.