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

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
<tile name>_line.shp <tile name>_line.dbf <tile name>_line.shx <tile name>_line.prj	Esri shapefiles for contour and tide line data.
<tile name>_point.shp <tile name>_point.dbf <tile name>_point.shx <tile name>_point.prj	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

UML diagram illustrating the data model for the contour data provided as an Esri shapefile.