As mentioned above, to aggregate search results, the aggregations type is used. The following query is simply requesting the maximum and minimum price of the result set.
You can also count the number of items satisfying a particular criterion by using the count field. The query below retrieves all the products as well as the variants belonging to the search term 'sofa'. Then we use the aggregations type to get the topic names and the amount of variants belonging to each of the topics returned.