Your current map provider gives you two things:
- A set of ’tiles’ (square map images) that are placed together to make the map
To switch to OpenStreetMap, you’ll need to replace both of these.
The map tiles, images of (usually) 256 x 256 pixels each, are drawn (“rendered”) from a map database.
If you currently use Google Maps, you’ll be using Google’s map tiles, hosted at google.com. Because the OpenStreetMap Foundation is a non-profit organisation with limited resources, you can’t just slot in the tiles from openstreetmap.org as a replacement (see the Tile Usage Policy). Instead, you can:
Generate your own tiles, by downloading the free OSM map database and rendering them;
Or use a third-party supplier (some of whom charge, some are free)
The OSM map database is called planet.osm. The full database and regular update files are both available at planet.openstreetmap.org.
Rendering your own tiles gives you complete control over their appearance. You can customise the maps to appear any way you like. Alternatively, third-party suppliers have OSM expertise and may have ready-prepared map styles that you can use.
OpenLayers – powerful and long-established
Leaflet – lightweight and easy-to-learn
Unlike commercial providers’ data, OpenStreetMap is ‘open data’. The map data is available to you free-of-charge, with the freedom to copy and modify. OSM’s licence is the Open Database Licence.
Your obligations are:
Attribution. You must credit OpenStreetMap with the same prominence that would be expected if you were using a commercial provider. See OSM’s copyright guidelines.
Share-Alike. When you use any adapted version of OSM’s map data, or works produced with it, you must also offer that adapted database under the ODbL.