﻿---
title: Bucket
description: Bucket aggregations don’t calculate metrics over fields like the metrics aggregations do, but instead, they create buckets of documents. Each bucket is...
url: https://www.elastic.co/elastic/docs-builder/docs/2697/reference/aggregations/bucket
products:
  - Elasticsearch
---

# Bucket
Bucket aggregations don’t calculate metrics over fields like the metrics aggregations do, but instead, they create buckets of documents. Each bucket is associated with a criterion (depending on the aggregation type) which determines whether or not a document in the current context "falls" into it. In other words, the buckets effectively define document sets. In addition to the buckets themselves, the `bucket` aggregations also compute and return the number of documents that "fell into" each bucket.
Bucket aggregations, as opposed to `metrics` aggregations, can hold sub-aggregations. These sub-aggregations will be aggregated for the buckets created by their "parent" bucket aggregation.
There are different bucket aggregators, each with a different "bucketing" strategy. Some define a single bucket, some define fixed number of multiple buckets, and others dynamically create the buckets during the aggregation process.
<note>
  The [`search.max_buckets`](/elastic/docs-builder/docs/2697/reference/elasticsearch/configuration-reference/search-settings#search-settings-max-buckets) cluster setting limits the number of buckets allowed in a single response.
</note>