# Esri Shapefile

Esri shapefiles are a simple, non-topological format for storing the geometric location and attribute information of geographic features. A shapefile is one of the spatial data formats that you can work with in ArcGIS.

The shapefile format defines the geometry and attributes of geographically referenced features in as many as five files with specific file extensions that should be stored in the same project workspace. The file extensions are as follows:

* .shp: The file that stores the feature geometry.
* .shx: The file that stores the index of the feature geometry.
* .dbf: The dBASE file that stores the attribute information of features. When a shapefile is added as a theme to a view, this file is displayed as a feature table.
* .sbn and .sbx: The files that store the spatial index of the features. These two files will only exist if you perform theme-on-theme selection, spatial joins or create an index on a theme's SHAPE field.
* .prj: The file that stores the projection information.

## Data structure <a href="#bookmark19" id="bookmark19"></a>

The layer structure of the Esri shapefile layers in the OS Terrain 50 contour supply is outlined in the following table.

| Layer name                                                                                                               | Layer description                                                                     |
| ------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------- |
| <p>\<tile name>\_line.shp</p><p>\<tile name>\_line.dbf</p><p>\<tile name>\_line.shx</p><p>\<tile name>\_line.prj</p>     | Esri shapefiles for contour and tide line data.                                       |
| <p>\<tile name>\_point.shp</p><p>\<tile name>\_point.dbf</p><p>\<tile name>\_point.shx</p><p>\<tile name>\_point.prj</p> | Esri shapefiles for spot height data.                                                 |
| Metadata\_\<tile name>.xml                                                                                               | A metadata file for contour data, providing information on the flying date and so on. |

## Detailed Esri shapefile model <a href="#bookmark20" id="bookmark20"></a>

<figure><img src="/files/WhnDhHQ4dHpTcHDmSIyj" alt="A UML data model for the point and line features provided as Esri shapefile data. Point and line data follow the same OS Terrain feature schema and can be related to one another through the &#x27;Geometry&#x27; Field type." width="394"><figcaption><p>UML diagram illustrating the data model for the contour data provided as an Esri shapefile.</p></figcaption></figure>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.os.uk/os-downloads/products/land-and-terrain-portfolio/os-terrain-50/os-terrain-50-technical-specification/esri-shapefile.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.