What is a GeoJSON?

GeoJSON is a format for encoding geographic data structures using JavaScript Object Notation (JSON). It’s a widely used format for representing geographic features, such as points, lines, and polygons, along with their associated data. GeoJSON can describe a wide range of geographic information like countries, cities, roads, and more.

A typical GeoJSON file contains:

1. Type: The type of GeoJSON object (e.g., “FeatureCollection”, “Point”, “Polygon”).
2. Features: A collection of geographic features, where each feature can include:
   • Geometry: The type of geometry (e.g., Point, LineString, Polygon) and the coordinates of the geometry.
   • Properties: Additional attributes or metadata associated with the feature, such as name, population, etc.

Here’s an example of a simple GeoJSON for a point feature:

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [102.0, 0.5]
      },
      "properties": {
        "name": "Sample Point"
      }
    }
  ]
}

In this example:

• “type” defines the object as a FeatureCollection.
• The feature has a geometry type of “Point” with specific coordinates.
• “properties” contains additional information about the point (in this case, a name).

Here is an additional example of two features captured in a GeoJSON:

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [102.0, 0.5]
      },
      "properties": {
        "name": "Sample Point",
        "description": "This is a sample point."
      }
    },
    {
      "type": "Feature",
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [102.0, 0.5],
            [103.0, 0.5],
            [103.0, 1.0],
            [102.0, 1.0],
            [102.0, 0.5]
          ]
        ]
      },
      "properties": {
        "name": "Sample Polygon",
        "description": "This is a sample polygon."
      }
    }
  ]
}

GeoJSON is used in mapping and geospatial applications, often for visualizing data on maps, making it compatible with many mapping libraries like Leaflet or Mapbox.