A class of problems concerned with finding or minimizing the sequence of change operations (such as insertion, deletion, substitution, or transposition) to convert one list or string into another

The Levenshtein distance is applied specifically to two string values. The result describes the number of differences between two strings. More specifically, it is the count of the smallest number of operations that can transform one string into the other string. Operations include the insertion, deletion, substitution, or transposition of a character in the string. Operations can be considered in combinations and may have different costs.

Here is a comprehensive list of Levenshtein functions in a variety of languages, however note that some languages have a standard utility function do to the same job.