[Yandex Cloud documentation](../../index.md) > [Yandex Object Storage](../index.md) > [Concepts](index.md) > Labels

# Labels

A _label_ is a key-value pair used for logical bucket and object labeling.

{% note info %}

Yandex Cloud uses _labels_ to logically identify resources. However, Object Storage supports compatibility with [Amazon S3 API](https://docs.aws.amazon.com/AmazonS3/latest/API/Welcome.html), that is why we use _tags_, a term native to AWS, in the [AWS CLI](../tools/aws-cli.md) commands and [API](../s3/index.md) parameters.

{% endnote %}

## Bucket labels {#bucket-tags}

Buckets support Yandex Resource Manager [labels](../../resource-manager/concepts/labels.md).


You can view spending details for buckets or other resources of Yandex Cloud [services](../../resource-manager/concepts/labels.md#services) marked with a specific label. For example, using labels, you can view expenses for a particular project or corporate department.

You can view expenses for the labeled resources in a CSV [file with usage details](../../billing/operations/get-folder-report.md#format) and on the [Yandex DataLens dashboard](../../billing/operations/dashboard.md).


Label operation limits:

* Maximum number of labels per resource: 64.
* Label key parameters:

  * It must be from 1 to 63 characters long.
  * It may contain lowercase Latin letters, numbers, hyphens, and underscores.
  * Use a letter for the first character.

* Label value parameters:

  * It may be up to 63 characters long.
  * It may contain lowercase Latin letters, numbers, hyphens, and underscores.

* Labels prefixed with `aws:` in the key are reserved for Object Storage. These labels are not counted in the total number of bucket labels. You cannot delete or modify them.

## Object labels {#object-tags}

You can work with object labels in the [management console](https://console.yandex.cloud) as well as in the [YC CLI](../../cli/quickstart.md), [AWS CLI](../tools/aws-cli.md), [Terraform](../../terraform/resources/storage_bucket.md), and [S3 API](../s3/index.md).

Object label operation limits are as follows:

* Maximum number of labels per object: 10.
* Label key parameters:
  * Up to 128 characters long.
  * May contain Latin letters, numbers, spaces, and these characters: `+`, `-`, `=`, `.`, `_`, `:`, `/`, and `@`.
* Label value parameters:
  * Up to 256 characters long.
  * May contain Latin letters, numbers, spaces, and these characters: `+`, `-`, `=`, `.`, `_`, `:`, `/`, and `@`.
* Labels prefixed with `aws:` in the key are reserved for Object Storage. These labels are not counted in the total number of object labels. You cannot delete or modify them.

#### See also {#see-also}

* [Managing bucket labels](../operations/buckets/tagging.md)
* [Managing object labels](../operations/objects/tagging.md)