Parity checking provides single-bit error detection for the system memory, but does not handle multi-bit errors, and provides no way to correct memory errors. An advanced error detection and correction protocol was invented to go a step beyond simple parity checking. Called ECC, which stands for error correcting circuits,error correcting code, or error correction code, this protocol not only detects both single-bit and multi-bit errors, it will actually correct single-bit errors on the fly, transparently. Like parity checking, ECC requires a setting in the BIOS program to be enabled. Often there are two; one turns on parity checking and the other tells the system to use ECC mode.
Parity Check提供記憶體單一位元錯誤檢查的能力，但是無法偵測多個位元的錯誤，而且無法更正錯誤的位元。
ECC: Error Correcting Circuits, Error Correcting Code, Error Correction Code的縮寫，可同時偵測一個或一個以上的錯誤位元，並且能自動更正單一一個位元的錯誤。
參考文獻
錯誤更正ECC：https://web.math.sinica.edu.tw/math_media/d184/18404.pdf (內有(7,4)Hamming解說)