Levenstein Algorithm

Levenshtein distance (LD) is a measure of the similarity between two strings, which we will refer to as the source string (s) and the target string (t).
The distance the minimum number of single-character edits (i.e. insertions, deletions or substitutions) required to change one word into the other.e.g

Lev(George, Georg) = 1
Lev(Prague, Prag ) = 2
Lev(Rome, Rom )    = 1

The greater the Levenshtein distance, the more different the strings are.