Richard Hamming introduced paper on hamming codes.
Hamming codes are used in error detection and correction.
Consider the data is being transmitted in a channel / medium with noise ,hence there is no guarantee that data originally sent will be received as same at the other end.
Hence hamming distance can help us find the error.
For example :
data 1 : 1101
data 2: 1011
Check if both strings have same digits in their respective places.If they match then mark 0 else 1 ,then add up the sum as below :
0+1+1+0 = 2
Hence we have Hamming distance = 2
Note : Hamming distance can be found for strings with same length.