Levenshtein distance - edit distance between two words using the operations insert / delete / replace . e.g. à dog – do 1 (delete operation)
Damerau-Levenshtein – Same as above but this includes transpose also. Hence cat à act has 2 Levenshtein distance, but only 1 Damerau-Levenshtein distance.
Best Regards,
Shreejay Nair