In anticipation of the 5.0 release, which will remove several deprecated query types from version 2.x, the article explains how to effectively use the bool query to handle complex boolean operations in Elasticsearch. It details the transition from traditional queries like filtered, and, or, and not, to the bool query's fields: must, must_not, should, and filter, which correspond to AND, NOT, OR, and filtering operations respectively. The bool query allows for the nesting of multiple boolean expressions to accommodate complex logical conditions, demonstrated through examples involving student preferences for fruit snacks. The should parameter differs from a standard boolean OR as it allows setting a minimum_should_match value to specify how many clauses should match for a document to be returned. Additionally, the filter field replaces deprecated filtered queries, enabling refined document searches without affecting relevance scores. The article emphasizes the importance of understanding these changes and testing extensively in preparation for the upgrade to version 5.0.