Bitrate - No of bits transferred per unit time
Baud rate - No of Symbols transferred per unit time
unit time may be anything - second,minute ....
bits means a single bit(1/0) but symbol consist of one or more than one bits
Baud rate = Bit rate / (No of bits transmitted per symbol)
In BPSK one bit is transmitted per symbol so Bit rate and baud rate is same But,
In QPSK 2 bit is transmitted per symbol so bit rate is double the baud rate.