# GeoPackage overview

The Open Geospatial Consortium (OGC) defines GeoPackage (\*.gpkg) an open, non-proprietary, platform-independent, standards-based data format for geographic information systems (GIS). It is designed to be a lightweight format that can contain large amounts of varied and complex data in a single, easy-to-distribute and ready-to-use file. GeoPackage is natively supported by numerous software applications.

GeoPackage offer users the following benefits:

* The single file is easy to transfer and offers a rich end-user experience.
* Attribute names are not limited in length, making the format user friendly.
* The file size limit is large at 140TB.

{% hint style="info" %}
A file size limit could be imposed by the file system to which the file is written.
{% endhint %}

* It supports raster, vector, and database formats, making it a highly versatile solution.
* It is an OGC standard.
* In most cases, it is a plug-and-play format.

For information on how to open, use and understand a GeoPackage dataset, please refer to our [Getting Started with GeoPackage](/os-downloads/resources/product-resources/getting-started-with-geopackage-and-vector-tiles-guides/getting-started-with-geopackage.md) guide. For further information on GeoPackage, please see the [GeoPackage website](https://www.geopackage.org/).

OS Open Rivers is supplied as a national GeoPackage file.

## Attribute mapping <a href="#id-5.1-attribute-mapping" id="id-5.1-attribute-mapping"></a>

The naming of attributes between GeoPackage and GML is very similar as both formats do not limit the number of characters for an attribute name. The tables in the following pages map the GML attribute name to its GeoPackage equivalent for the WatercourseLink and HydroNode features:

* [WatercourseLink](/os-downloads/products/water-portfolio/os-open-rivers/os-open-rivers-technical-specification/geopackage-overview/watercourselink.md)
* [HydroNode](/os-downloads/products/water-portfolio/os-open-rivers/os-open-rivers-technical-specification/geopackage-overview/hydronode.md)

{% hint style="info" %}
GML includes attributes which describe the geometry of the features; this is not applicable to GeoPackage files as they are separated by their geometry.

The use of an asterisk symbol (\*) in the tables indicates that a particular attribute is not mapped in that format, for example, centrelineGeometry attribute has no GeoPackage equivalent.
{% endhint %}

{% hint style="info" %}
In April 2023, there were significant changes to the naming patterns in the GeoPackage format. These are outlined in [GeoPackage format changes](/os-downloads/products/water-portfolio/os-open-rivers/os-open-rivers-technical-specification/geopackage-overview/geopackage-format-changes-april-2023.md).
{% endhint %}


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