Source : Free On-Line Dictionary of Computing

data bus
     
         The bus (connections between and within the
        {CPU}, memory, and peripherals) used to carry {data}.  Other
        connections are the {address bus} and control signals.
     
        The width and {clock rate} of the data bus determine its data
        rate (the number of {bytes} per second it can carry), which is
        one of the main factors determining the processing power of a
        computer.  Most current processor designs use a 32-bit bus,
        meaning that 32 bits of data can be transferred at once.  Some
        processors have an internal data bus which is wider than their
        external bus in order to make external connections cheaper
        while retaining some of the benefits in processing power of a
        wider bus.
     
        See also {data path}.
     
        (1995-01-16)