Acrylonitrile Butadiene Styrene (ABS) is a type of plastic pipe used most often in drains. It is usually black, which makes it easy to tell apart from PVC. Use with the [plumbing] and [drain] tags.
ABS pipe is a plastic pipe similar to PVC. Typically pvc is white, cpvc is yellow and ABS is black. ABS contains bisphenol A, or BPA, which is a chemical some people are concerned about. ABS is never used for water supply lines, however, only drains since (like PVC) it does not handle hot water well.
Some localities restrict the use of ABS now. Check local restrictions before using.