Woven yarns are strands of fibers that have been interlaced together to form a fabric. The term 'wefts' refers to the threads that are woven across the warp threads in a weaving process. Wefts are usually made from the same material as the warp threads, but can also be made from different materials. Wefts are used to create patterns and textures in fabrics, and are an essential part of the weaving process.