=== What about Facets?
If you've used Elasticsearch in the past, you are probably aware of facets. You can think of Aggregations as "facets on steroids". Everything you can do with facets, you can do with aggregations.
But there are plenty of operations that are possible in aggregations which are simply impossible with facets.
Facets have not been officially depreciated yet, but you can expect that to happen eventually. We recommend migrating your facets over to aggregations when you get the chance, and starting all new projects with aggregations instead of facets.