N-grams index substrings for partial matching. "search" with : ["sea", "ear", "arc", "rch"]. Enables prefix, suffix, and infix queries without wildcards.
Edge n-grams index prefixes only: ["s", "se", "sea", "sear", "searc", "search"]. Perfect for autocomplete. Trade-off: larger index size. Configure min/max n-gram length to balance precision and index size.