Knitting yarn is a type of yarn used for making garments and other items by hand. The two most common types of knitting yarn are WORSTED and WOOL. WORSTED yarn is a medium-weight yarn made from combed long-staple fibers, usually WOOL, that have been tightly twisted together. WOOL yarn is a type of yarn made from the fleece of sheep or other animals, such as alpaca or mohair. It is often used for sweaters, hats, scarves, and other warm items.