Etymology: J.M.E. Baudot, French inventor, b. 1845
a measure of data flow or the speed with which a computer device transmits information.
A unit of data transmission equal to 1 bit/sec. Technically, baud is the number of times/sec that the carrier signal shifts value—e.g., a 56k bit-per-second modem actually runs at 14.4 baud, but it moves 4 bits per baud. Named after a Emile Baudot 1845-1903, a French telegraph engineer, inventor of the Baudot code, and pioneer of telecommunication.
Once the information is sent in a reasonably trouble-free fashion, you may want to cut the error rate to a minimum by optimizing the communication parameters: baud rate, parity, word length, and stop bits.