Levenshtein Distance : The minimum number of single-character edits required to change one word into the other. Strings do not have to be the same length

Hamming Distance : The number of characters that are different in two equal length strings.

Smith–Waterman : A family of algorithms for computing variable sub-sequence similarities.

Sørensen–Dice Coefficient : A similarity algorithm that computes difference coefficients of adjacent character pairs.

Damerau Levenshtein distance is another algorithm for comparing two strings and it is similar to the Levenshtein distance algorithm. The difference between the two is that it can also check transpositions between characters and hence may give a better result for error correction. – levenshtein, (Levenshtein)