title: What's the difference between query_string and multi_match?
body: <p>When running this queries:</p>
  
  <pre><code>{
    "query_string" : {
      "query" : "text",
      "fields": ["field1", "field2"]
    }
  }
  </code></pre>
  
  <p>-</p>
  
  <pre><code>{
    "multi_match" : {
      "query" : "text",
      "fields": ["field1", "field2"]
    }
  }
  </code></pre>
  
  <p>What is the difference? When to use one and when to use the other?</p>