Only users with the [organization administrator role]({{< relref "../administration/roles-and-permissions#organization-roles" >}}) can add or remove data sources.
To access data source management tools in Grafana as an administrator, navigate to **Configuration > Data Sources** in the Grafana sidebar.
For details on data source management, including instructions on how to add data sources and configure user permissions for queries, refer to the [administration documentation]({{< relref "../administration/data-source-management" >}}).
Each data source's **query editor** provides a customized user interface that helps you write queries that take advantage of its unique capabilities.
You use a data source's query editor when you create queries in [dashboard panels]({{< relref "../panels-visualizations/query-transform-data" >}}) or [Explore]({{< relref "../explore/" >}}).
Because of the differences between query languages, each data source query editor looks and functions differently.
Depending on your data source, the query editor might provide auto-completion features, metric names, variable suggestions, or a visual query-building interface.
For example, this video demonstrates the visual Prometheus query builder:
{{<vimeo720004179>}}
For general information about querying in Grafana, and common options and user interface elements across all query editors, refer to [Query and transform data]({{< relref "../panels-visualizations/query-transform-data/" >}}).
- **Grafana:** A built-in data source that generates random walk data and can poll the [Testdata]({{< relref "./testdata/" >}}) data source. Additionally, it can list files and get other data from a Grafana installation. This can be helpful for testing visualizations and running experiments.
- **Mixed:** An abstraction that lets you query multiple data sources in the same panel.
When you select Mixed, you can then select a different data source for each new query that you add.
- The first query uses the data source that was selected before you selected **Mixed**.
- You can't change an existing query to use the **Mixed** data source.
- Grafana Play example: [Mixed data sources](https://play.grafana.org/d/000000100/mixed-datasources?orgId=1)
- **Dashboard:** A data source that uses the result set from another panel in the same dashboard. The dashboard data source can use data either directly from the selected panel or from annotations attached to the selected panel.
