To help meet their immediate needs for cash, banks and corporations sometimes issue unsecured, short-term debt instruments known as commercial paper.
Commercial paper usually matures within a year and is an important part of what's known as the money market.
It can be a good place for investors -- institutional investors in particular -- to put their cash temporarily. That's because these investments are liquid and essentially risk-free, since they are typically issued by profitable, long-established, and highly regarded corporations.