You can control how Atlas Search turns a
string field's contents into searchable
terms using analyzers. Analyzers are policies that combine a tokenizer, which
extracts tokens from text, with filters that you define. Atlas Search
applies your filters to the tokens to create indexable terms that correct for differences
in punctuation, capitalization, filler words, and more.
To control how Atlas Search creates search terms, use an Atlas Search analyzer in the index definition. You may specify an analyzer when creating an index, executing a query, or both.
Atlas Search provides the following built-in analyzers:
Uses the default analyzer for all Atlas Search indexes and queries.
Divides text into searchable terms wherever it finds a non-letter character.
Divides text into searchable terms wherever it finds a whitespace character.
Provides a set of language-specific text analyzers.
Indexes text fields as single terms.
If you don't specify an analyzer, MongoDB uses the default standard analyzer.