Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It has both medical and industrial uses. Coal tar solution is a dark, viscous liquid derived from coal tar that has a variety of uses and applications. It is commonly used in the treatment of skin conditions such as psoriasis, eczema, and dandruff, as well as in the production of asphalt and other industrial products. Coal tar solution is also used as a wood preservative and as a component in some types of paints and coatings. Its antiseptic and anti-inflammatory properties make it a valuable ingredient in many medicinal and cosmetic products.