n-gram is a method to split words into set of substring elements so that those can be used to match words.
Use the following examples to get your first idea about it. I created two columns so that we could compare the n-grams of two different words side-by-side.
L Ma (2019). 'n-gram', Datumorphism, 05 April. Available at: https://datumorphism.leima.is/cards/math/n-gram/.