Knitting is a method by which thread or yarn is used to create a cloth. Knitted fabric consists of a number of consecutive rows of loops, called stitches. As each row progresses, a new loop is pulled through an existing loop. Knitting may be done by hand or by machine. There exist numerous styles and methods of hand knitting. Different types of yarns and needles may be used to achieve a plethora of knitted materials; these tools give the final piece a different colour, texture, weight, and/or integrity. Other factors that affect the end result include the needle's shape, thickness and malleability, as well as the yarn's fibre type, texture and twist.