Source : WordNet®

data rate
     n : the rate at which circuits or other devices operate when
         handling digital information

Source : Free On-Line Dictionary of Computing

data rate
     
         (Or "data ransfer rate", "transmission
        rate") The amount of {data} transferred per second by a
        communications channel or a computing or storage device.
     
        Data rate is measured in units of {bits per second} (written
        "b/s" or "bps"), {bytes per second} (Bps), or {baud}.
     
        When applied to data rate, the multiplier {prefixes} "kilo-",
        "mega-", "giga-", etc. (and their abbreviations, "k", "M",
        "G", etc.) always denote powers of 1000.  For example, 64 kbps
        is 64,000 bits per second.  This contrasts with units of
        storage where they stand for powers of 1024, e.g. 1 KB = 1024
        bytes.
     
        [Relationship with "{bandwidth}"?]
     
        (2002-03-23)