Can you explain in details that what is coal tar?

Coal tar: It is a black, thick liquid with unpleasant smell obtained from the destructive distillation of coal. It is a mixture of about 200 substances. Products obtained from coal tar are used as starting materials for manufacturing various substances used in everyday life and in industry, like synthetic dyes, drugs, explosives, perfumes, plastics, paints, photographic materials, roofing materials, etc.

Naphthalene balls used to repel moths and other insects are also obtained from coal tar.