Bit Rate is the number of bits that pass a given point in a telecommunication network in a given amount of time, usually a second. Thus, a bit rate is usually measured in some multiple of bits per second - for example, kilobits, or thousands of bits per second ( Kbps ).
The term bit rate is a synonym for data transfer rate (or simply data rate ). Bit rate seems to be used more often when discussing transmission technology details and data transfer rate (or data rate ) when comparing transmission technologies for the end user.