Yarn is a long strand of fibers that is used for knitting, crocheting, and weaving. It can be made from various materials, including wool, cotton, acrylic, and silk. The thickness and texture of yarn can vary, allowing for different types of projects and styles. Yarn comes in many colors and can be purchased in skeins or balls. It is often labeled with information about its weight, which helps crafters choose the right type for their projects. Many people enjoy using yarn to create items like sweaters, scarves, and blankets, making it a popular choice for both beginners and experienced crafters.