Edit distance is the measurement of how close a possibly misspelt word is to a correct spelt word.
Levenshtein edit distance is one type of edit distance where it counts how many inserts, deletions, and replaced characters one word is from another.
Damerau-Levenshtein edit distance is similar the the above but considers characters might have been typed out of order.
Weighted edit distance is like the above except that possible errors have weights where one spelling correction would be more likely than another.
Jesse Michael
