Can someone please explain how the Hamming Code works?

A Hamming Code is an algorithm that can be used to determine if an error exists in a data stream, and sometimes (dependent on the exact code used) correct that error. This is sometimes referred to as an Error Correction Code (ECC).The number of Hamming Code drives in a RAID array is designated by the number after the first plus sign (‘+’). If there is no first plus sign, then there are no Hamming Code drives. This is the same location that the parity number is found in. Except for RAID-1, if the valueis one, then it is a parity drive; if it is greater than one, then they are Hamming Code drives.