Source : Free On-Line Dictionary of Computing

error detection and correction
     
         (EDAC, or "error checking and
        correction", ECC) A collection of methods to detect errors in
        transmitted or stored data and to correct them.  This is done
        in many ways, all of them involving some form of coding.  The
        simplest form of error detection is a single added {parity
        bit} or a {cyclic redundancy check}.  Multiple parity bits can
        not only detect that an error has occurred, but also which
        bits have been inverted, and should therefore be re-inverted
        to restore the original data.  The more extra bits are added,
        the greater the chance that multiple errors will be detectable
        and correctable.
     
        Several codes can perform Single Error Correction, Double
        Error Detection (SECDEC).  One of the most commonly used is
        the {Hamming code}.
     
        At the other technological extreme, cuniform texts from about
        1500 B.C. which recorded the dates when Venus was visible,
        were examined on the basis of contained redundancies (the
        dates of appearance and disappearance were suplemented by the
        length of time of visibility) and "the worst data set ever
        seen" by [Huber, Zurich] was corrected.
     
        {RAM} which includes EDAC circuits is known as {error
        correcting memory} (ECM).
     
        [Wakerly, "Error Detecting Codes", North Holland 1978].
     
        [Hamming, "Coding and Information Theory", 2nd Ed, Prentice
        Hall 1986].
     
        (1995-03-14)