A block of soap is a solid piece of soap that is usually rectangular in shape and can be used for washing hands, body, and other surfaces. It is typically made from a combination of fats or oils and an alkali, such as sodium hydroxide. The BAR of soap is the most common form of soap, and it is often scented with various fragrances. The term 'BAR' refers to the shape of the soap, which is usually rectangular or cylindrical.