GeoJSON is a data-interchange format for a variety of geographic data structures. GeoJSON can be used to represent a geometry, a feature, a collection of geometries, or a collection of features. The geometry types supported in GeoJSON are Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, and Box. Features in GeoJSON are geometry objects with additional properties. A geometry collection represents a list of geometries and a feature collection represents a list of features.

A complete GeoJSON data structure is always an object (in JSON terms). In GeoJSON, an ''object'' consists of a collection of name/value pairs - also called ''members''. For each ''member'', the name is always a ''string''. Member ''values'' are either a ''string'', ''number'', ''object'', ''array'' or one of the literals: '''true''', '''false''', and '''null'''. An ''array'' consists of elements where each element is a ''value'' as described above. Note that the term ''member'' generally refers to a name/value pair.

A complete GeoJSON data structure is always an object (in JSON terms). In GeoJSON, an ''object'' consists of a collection of name/value pairs - also called ''members''. For each ''member'', the name is always a ''string''. Member ''values'' are either a ''string'', ''number'', ''object'', ''array'' or one of the literals: '''true''', '''false''', and '''null'''. An ''array'' consists of elements where each element is a ''value'' as described above. Note that while the term ''member'' generally refers to a name/value pair, GeoJSON does use the name "members" in geometry collections and feature collections.

### Geometry objects may also have a member with the name "crs" which specifies the coordinate reference system of the coordinates. If present, the value of the crs member must be an object. The structure of that object is beyond the scope of this specification.