---
title: "Glossary | Grafana Enterprise Metrics documentation"
description: "Grafana Enterprise Metrics glossary"
---

# Glossary

Commonly used terms and abbreviations within Grafana Enterprise Metrics documentation are as follows:

Expand table

| Term          | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Access policy | An access policy is a resource that contains a granular set of permissions which specify what actions a request to GEM is allowed to do. In GEM, access policies are created with the desired set of permissions. Then API tokens can be generated that are associated with a particular access policy. You can also [Configure GEM to integrate with an OAuth backend](/docs/enterprise-metrics/latest/manage/oauth/) to externally generate tokens associated with a particular access policy.                                                       |
| Cluster       | A cluster is a licensed deployment of Grafana Metric Enterprise. Clusters are uniquely named and must have a corresponding license.                                                                                                                                                                                                                                                                                                                                                                                                                    |
| Tenant        | A tenant is scoped to a particular cluster. New samples can be written to a tenant and queries can be issued to a particular tenant. Each tenant will store its metrics in a separate set of [TSDB blocks](https://ganeshvernekar.com/blog/prometheus-tsdb-the-head-block/) that are stored in the configured storage bucket. The blocks themselves will be stored in the bucket with the name of the tenant as a prefix. This means once a tenant is created, its *name* cannot be changed. However, the *display\_name* for a tenant can be changed. |
| Token         | A token is a randomly generated string that can be used as an API key when making requests to GEM.                                                                                                                                                                                                                                                                                                                                                                                                                                                     |