Levenshtein distance calculates the number of operations needed to change one word to another by applying single-character edits (insertions, deletions or substitutions).
The reference explains this concept very well. For consistency, I extracted a paragraph from it which explains the operations in Levenshtein algorithm. The source of the following paragraph is the first reference of this article.
L Ma (2019). 'Levenshtein Distance', Datumorphism, 05 April. Available at: https://datumorphism.leima.is/cards/math/levenshtein-distance/.