Here's a breakdown of the terms:

* Soot is a general term for black powdery material consisting mostly of carbon particles. It's formed by the incomplete combustion of fuels like wood, oil, and coal.

* Carbon black is a specific type of soot produced by the incomplete combustion of hydrocarbons in a controlled environment. It's used as a pigment, filler, and reinforcement agent in various industries.

Both terms are used interchangeably in many contexts, but "carbon black" is more specific and indicates a high-purity form of soot with defined properties.