Direct answer: Black tar is usually a colour-based description for dark tarry material, not a precise material type. In tar.fyi/ usage, it means black wood, coal, bitumen, or pitch-like material depending on context.
Many tars are dark brown to black because of carbon-rich compounds and heavy organic residues. Coal tar, pine tar, road residue, pitch, and bitumen can all be black or nearly black, even when their sources differ.
People may say black tar when they mean roofing tar, road tar, pine tar, coal tar, or pitch. In some contexts the phrase has unrelated illicit-drug meanings, so a materials article should state clearly that it is discussing tar as a substance, coating, or historical material.
Colour alone does not identify a tar. A black pine tar and a black coal-tar pitch can share appearance while having different chemistry, hazards, smell, and uses.
In short: A colour description, not a precise material class. Can refer to wood tar, coal tar, pitch, bitumen, or road residue. Context is essential. This article concerns materials only.