Bit rate vs. Baud rate

Bit rate: The transmission of number of bits per second. 

Baud rate: The number of signal units per second. 

Bit rate = Baud rate * number of bits per baud 

 In digital systems 1 Bd = 1 bit/sec.  

The symbol duration time Ts:

  Can be measured as the time between the transitions in an eye diagram of the signal in an oscilloscope. 

Ts = 1 / fs, Fs is the symbol rate.

A common measure of the symbol rate is the baud (Bd). 

 Communication at the baud rate 1000 Bd, means communication by sending 1000 symbols per second. 

For a modem: This corresponds to sending 1000 tones per second. 

For a line code: This corresponds to 1000 pulses per second.