The Unix software device that discards any data written to it and supplies zero bytes of data when read. /dev/null is occasionally useful in situations where a file is required but no relevant file exists. For example, if a program produced lots of output for debugging purposes but that output was not required when the program was deployed in a production environment and writing it to a file would waste disk space then the output could be written to /dev/null. The term is used for a notional "black hole" in any information space. For example, a message, might end, "Kudos to rasputin-at-kremlin.org, flames to /dev/null". See bit bucket.

Free Online Dictionary of Computing