Difference between search score and explain value?

Elastic Stack Elasticsearch
1

Hi,

I'm seeing a search result where there is a big difference between the score returned in the search vs the score when it's explained. In general, I also noticed that the two scores are not exactly the same. What is the difference between them?

Here's a snippet of the search results with explain on:

  {
    "_shard": 4,
    "_node": "KjOdjnQqQ-yQ3a0hvhlTcA",
    "_index": "index",
    "_type": "type",
    "_id": "id",
    **"_score": 0.6251602,**
    "_source": {
      .....
    },
    "_explanation": {
      **"value": 7.0064363,**
      "description": "product of:",
      "details": [
        {
          "value": 12.845133,
          "description": "sum of:",
          "details": [
          ........
          ]
        },
        {
          "value": 0.54545456,
          "description": "coord(6/11)",
          "details": []
        }
      ]
    }
  },

Thanks,
Kevin