title: elasticsearch multi_match vs should
body: <p>Can someone tell me the difference between</p>
  
  <pre><code>"query": {
      "bool": {
          "should": [
              { "match": {"title": keyword} },
              { "match": {"description": keyword} }
          ]
      }
  </code></pre>
  
  <p>and</p>
  
  <pre><code>"query": {
          "multi_match": {
              "query": keyword,
              "fields": [ "title", "description" ]
          }
      }
  </code></pre>
  
  <p>Is there any performance turning if choose one of two above?</p>