Code having sufficient intelligence and incorporating sufficient signaling information to enable the detection and correction of many errors at the receiver.

Code incorporating sufficient additional signaling elements to enable the nature of some or all of the errors to be indicated and corrected entirely at the receiving end.

a systematic way to encode messages into codewords, incorporating enough redundancy in the process to enable recovery of the correct message upon receipt of an erroneous codeword

an algorithm for expressing a sequence of numbers such that any errors