# MetricLabel.msg

## Overview

`MetricLabel.msg` is a single key/value label attached to a metric. Labels allow the same family of metrics to distinguish between different dimensions, such as the trajectory or map being measured.

## Fields

| Field | Type | Description |
| --- | --- | --- |
| `key` | `string` | The label key (e.g., a dimension name). |
| `value` | `string` | The label value for this metric instance. |

## Usage

- `MetricLabel` instances are stored in the `labels` array of `Metric.msg`.
- A set of labels uniquely identifies one instance of a metric family.