Elasticsearch Relevance Score_score

Purpose of relevance score _score

It is to sort the results of the current query, and it is not meaningful to compare the relevance scores of different query results.

How _score is calculated

score(q,d)  =  
            queryNorm(q)  
          · coord(q,d)    
          · ∑ (           
                tf(t in d)   
              · idf(t)²      
              · t.getBoost() 
              · norm(t,d)    
            ) (t in q)