Trigram search is a method of searching

Search algorithm

In computer science, a search algorithm is an algorithm for finding an item with specified properties among a collection of items. The items may be stored individually as records in a database; or may be elements of a search space defined by a mathematical formula or procedure, such as the roots...

 for text when the exact syntax

Syntax

In linguistics, syntax is the study of the principles and rules for constructing phrases and sentences in natural languages....

 or spelling of the target object is not precisely known. It finds objects which match the maximum number of three-character strings in the entered search terms, i.e. near matches. A threshold can be specified as a cutoff point, after which a result is no longer regarded as a match.