Direct answer: Raw tar is unrefined tar as it first comes from a kiln, retort, coke oven, or other production process. It contains a variable mixture of water, oils, resins, solids, and heavy tarry compounds.
Raw tar reflects its source material. Raw pine tar from resinous wood is different from raw coal tar from coke production or raw birch tar from bark. Older makers often allowed crude tar to settle, thicken, or be strained before sale or use.
Raw tar may appear in historical craft, industrial processing, and old trade descriptions. It is usually a starting material rather than a carefully standardised consumer product. Refining, settling, blending, or distillation may turn it into more predictable grades.
Raw tar is a condition, not a species. You still need to know whether it is wood tar, coal tar, peat tar, or another tar. The word raw simply means comparatively unprocessed.
In short: Unrefined or minimally processed tar. Can come from wood, coal, bark, peat, or other feedstocks. Composition varies widely. Usually needs context before practical conclusions can be drawn.