Parity Redundancy in RAID
The concept of parity and checksum data has been used for many years in computer science to verify that data that has been transmitted has been transmitted accurately, without corruption. The basic concept of the checksum involves a sending node calculating a checksum value based on the data values that it was transmitting. This checksum value would then be placed at the end of the transmission.
A receiving node receives the transmission and calculates its own checksum value for the data. If the receiver's checksum matched the transmitter's checksum, the data was considered to be accurate. If not, the receiver would discard the data and the transmitter would have to resend it.
RAID applies a similar concept, but instead ...