In common usage, the "baud rate" of a modem is how many bits it can send or receive per second. Technically, baud is the number of times per second that the carrier signal shifts value. A 1200 bit-per-second modem actually runs at 300 baud, because it moves 4 bits per baud (4 x 300 = 1200 bits per second). Using baud is no longer fashionable, however, having been replaced by the more direct "bits per second" (bps).
NetLingo Classification: Net Technology