The term "woolen sweater" originally refers to a sweater made of wool, which is also recognized by ordinary people. In fact, "woolen sweater" has become a synonym for a class of products, which is generally used to refer to "knitting sweater" or "woolen knitwear". Woolen knitwear refers to the fabrics made from wool, cashmere, rabbit wool and other animal wool fibers as the main raw materials, such as rabbit sweater, snow orchid sweater, wool sweater, acrylic sweater and so on.
Sweater clothing is generally called sweater clothing, also known as wool knitted clothing, is knitted clothing woven with wool yarn or wool type chemical fiber yarn. Hand-knitted woolen garments appeared in the Euphrates and Tigris river basins of western Asia around 1000 BC. Machine-knitted wool garments appeared in modern times. In 1862 AD, American R.I.W. ram invented a double-reverse flat knitting machine, on which woolen sweaters were produced into forming pieces for stitching into garments, marking the beginning of machine-knitted wool garments.