Error Detection                         Error Correction
==========================================================================

Add enough redundant bits to each       Add enough redundant bits to each
frame so that the receiver (w.h.p.)     frame so that the receiver (w.h.p.)
can detect errors and discard invalid   can detect errors and fix them on
frames, and request a retransmission    their own, without any retransmission

Examples:                               Examples:
 Horizontal parity                       Horizontal + vertical parity together
 Vertical parity                         Sparse codes
 Internet checksum (TCP, UDP, IP)        Hamming codes
 Cyclic Redundancy Check (CRC)           Reed-Solomon codes