Key Differences between OpenStreetMap and Leaflet

Feature	OpenStreetMap (OSM)	Leaflet
Type	Map data platform / geographic database	JavaScript software library (frontend tool)
Primary Function	Collects, stores & serves geographic data and map tiles	Draws interactive maps, markers, popups and layers in a browser
Data Source	Crowdsourced by global contributors	Can use OpenStreetMap, Mapbox, Stamen, Google Maps or other tile providers
Customisation	Limited control over base map styling directly through the platform	Extensive front-end customisation for styles, markers and plugins
Relationship	Often acts as the data/tile provider for a map	Often acts as the renderer that displays OSM tiles on a website