Yarn is a long, continuous length of fibers that have been spun or felted together. Yarn is used to make cloth by knitting, crocheting or weaving. Yarn is sold in the shape called a skein to prevent the yarn from becoming tangled or knotted.
Yarn can be made from any number of natural or synthetic fibers such as wool, cotton, silk, or acrylic. Some yarns are made from a blend of several kinds of fibers.
Yarns come in many thicknesses or weights from fine to thick: lace, fingering, sock, sport, double-knit (or DK), worsted, aran, bulky, and super-bulky. Very fine yarn is called thread and is used in sewing and embroidery.
Yarn can also be used to crochet.