# Metadata

Metadata is a description of your dataset. It helps the library understand the type and format of your data, so that it can apply the correct metrics. 

{% hint style="danger" %}
If the metadata is incorrect, this library may apply the wrong metrics to your data which leads to inaccurate scores.
{% endhint %}

Your metadata includes:

* The type of data that each column represents
* The primary keys and other identifiers of the table
* The relationships between the tables, if you have multiple tables

{% hint style="success" %}
Write your metadata once and use it anywhere in the SDMetrics library.

If you used the SDV library to create your metadata, you can reuse the same file for SDMetrics.
{% endhint %}