I strongly disagree that crc, in itself, can correct the errors, it only detects errors and normally, once crc detects the errors it asks to send the data again, that is how the correct data is received when there is an error, with reed solomon codes, or other error correcting codes, once the data is received, by itself, any errors that is within the error number that the code can correct, will be automatically corrected, and it does not need to resend data, all it needs is the data either corrupt or valid. It's like reading a sentence, when you read a word in the sentence that is mispelled, you correct it right away,(error correcting codes), or you could ask for another copy of the article you are reading(error detecting code)