A hair weave is a very general term used to describe human or artificial hair used to alter one's natural hair appearance by adding additional hair to their natural hair or by covering the natural hair all together with human or synthetic hair pieces. The highest quality extension hair is human remy hair. Remy hair still possesses the cuticle layer, which is the outermost part of the hair strand; it resembles shingles on a roof. All remy hair has the cuticle layer of the hair flowing in the same direction, flowing the way it would naturally. The cuticle layer is important when concerned with hair tangling, longevity of the use (up to one year), and how well the hair shines. When the cuticle layer is intact and laying flat, the hair is capable of reflecting light, resulting in the hair shining.