Field boosting assigns different ranking weights to matching terms according to their document fields. A query can give matches in a title more influence than matches in a description, extending the default BM25 keyword score with configurable scoring functions. section 3.2.2
Title matches outweigh description matches
For the query “the cat in the hat,” setting title^10 and description^2.5 makes a title match contribute more strongly to relevance than an equivalent description match. The same request can be expressed through a generic search API or translated into engine-specific syntax. section 3.2.2
