Query Pagination

Query results are limited to a page size of 10 by default

Query pagination and page number controlled by From/Size parameters:

curl -XPOST 'localhost:9200/orders/_search?pretty=true' \
-H 'content-type: application/json' \
-d '
{ 
  "from":0, 
  "size":2, 
  "query": {
    "match_all":{}
  }
}'

Expected result (partially presented):

{
...
"hits" : {
  "total" : {
    "value" : 1,
    "relation" : "eq"
  },
  "max_score" : 1.0,
  "hits" : [
    {
      "_index" : "orders",
      "_id" : "1",
      "_score" : 1.0,
      "_source" : {
        "id" : "1",
        "placedOn" : "2016-10-17T13:03:30.830Z"
      }
    },
    ...
  ]
}
}

Note hits.total.value field, what does it stand for?
How results are sorted?