Baud rate is the number of change in signal-state/ pulse/symbol per second in a communication channel.
For example :- A baud rate of 1 kBd = 1000 Bd is synonymous to a symbol rate of 1,000 symbols per second. In case of a modem, this corresponds to 1,000 tones per second, and in case of a line code, this corresponds to 1,000 pulses per second. The symbol duration time is 1/1,000 second = 1 millisecond.
Also if any circuit shows a baud rate of 9600, that means circuit changes its signal-state 9600 times in a second. Signal-State change can include 0 to 1 or vice versa.
The symbol rate is related to but should not be confused with gross bit rate expressed in bit/s.
Bandwidth is depend on baud rate.
Bit Rate is the number of data bits (i.e. ‘0’ or ‘1’) transferred per second in a communication channel.
For example :- A bitrate of 2400 means there are 2400 ‘0’s or ‘1’s to be transmitted across communication channel in 1 second.Date rate is depend on bit rate
The main difference between the two is that one change of state can transmit one bit, or slightly more or less than one bit, that depends on the modulation technique used. So the bit rate (bps) and baud rate (baud per second) have this connection: