A unit used in engineering for measuring the rate of data transmission over telegraph or telephone lines. The baud rate is the number of distinct symbols transmitted per second, that is, the number of times per second the signal carrying the communication varies in strength or frequency. In the days of the telegraph, the signal increased at the start of a pulse and decreased at the end, so the baud rate was 2 times the number of dots that could be transmitted per second. In recent years, when the baud has been used to represent digital data transmission, the definition has varied according to the technique used. If the symbols transmitted have only two states (on or off) then the baud rate is the same as the transmission rate in bits per second. This was the case in early modems, but in modern data transmission equipment symbols have a much larger number of possible states. For example, if the signal has 28 = 256 possible states, then a single symbol can carry 8 bits of information and the bit rate will be 8 times the baud rate. Consequently, any use of "baud" as a synonym for "bits per second" is incorrect. The baud is named for the French telegraph engineer J. M. E. Baudot (1845-1903), the inventor of the first teleprinter