This document provides an overview of yarns, their classification, and characteristics. It discusses the key differences between spun/staple yarns and filament yarns. Spun yarns are made from short fibers that are twisted together, while filament yarns use continuous fibers. Yarn twist and count affect properties like strength and fineness. There are many types of yarns including novelty yarns which have decorative elements, and textured yarns that use new spinning techniques to alter the surface and shape. Textured yarns can be made to stretch or provide bulk. Overall, the document covers the fundamental types and characteristics of yarns used in textile manufacturing.