Direct answer: Tar soap is soap made with a tar ingredient, most often pine tar or coal tar in historical and specialist products. It should be discussed as a formulated product, not as raw tar.
Tar soaps grew from the long association between tarry materials, strong odours, cleansing products, and older topical traditions. Pine tar soaps became especially recognisable in rustic and traditional personal-care markets. Coal tar also has a separate regulated medical-product history.
People search tar soap because of scent, tradition, dandruff products, skin history, or curiosity about old-fashioned soap. A safe article can explain ingredient types and history without offering treatment claims.
Pine tar soap and coal tar soap are not the same. Finished soap and raw tar are not the same. A cosmetic bar, an over-the-counter medicated product, and a homemade novelty soap may sit under similar search terms but face different rules.
In short: A soap containing a tar-derived ingredient. Most often associated with pine tar or coal tar. Finished soap differs from crude tar. Medical or skin claims require proper regulated evidence.