The term “cotton wool” can refer to two products: raw, minimally processed cotton and a form of cotton that has been processed to be especially absorbent. There are a variety of uses for these materials, and both forms of the product are typically readily available in stores, especially those that stock medical and cosmetic supplies.
In the first sense, cotton wool is raw cotton that has been combed to remove impurities and then cleaned to sterilize it. Tufts of raw cotton do look rather like hunks of wool, explaining the name. The texture is generally very silky and soft, and it can sometimes be a bit squeaky, depending on how it is processed. One common use for this type of cotton is as a vehicle for makeup remover, which can be poured onto it and then swabbed across the face.
More refined cotton wool is made by combing raw cotton, bleaching it, sterilizing it, and then processed in a variety of ways. One form is the cotton ball, made to resemble classic raw cotton. Refined cotton can also be used to make bandages, medical swabs, and other similar products; because it is sterilized, it can also be used to pack wounds and in other surgical tasks. Most medical offices have an many examples of this type of cotton.
Many people keep some cotton products around the house, because they can be extremely useful. For example, cotton dressings can be used to pad a wound before bandaging, if the wound is especially large, to absorb some of the blood. Cotton balls can also be used with nail polish remover and a variety of other cosmetics. They can also be stuck between the toes while painting nails, or soaked in things like milk and applied to closed eyes to reduce swelling and puffiness.
For consumers who are concerned about the use of pesticides and herbicides on crops, some companies make organic cotton wool, which may be bleached using natural processes. These products will generally be more expensive, because of the additional labor involved in growing and harvesting the cotton.