When you add a tile layer to your Leaflet map, you are telling the map where to fetch the actual map images from. In the code above, the L.tileLayer function is used to specify the URL template for OpenStreetMap tiles. The curly braces in the URL ({s}, {z}, {x}, {y}) are placeholders that Leaflet replaces with the correct values as you move around the map or zoom in and out.

The attribution option is included as part of the tile layer configuration. This displays a small credit on the map, usually in a corner, showing where the map data comes from. Proper attribution is not just a courtesy; it is a legal requirement when using most third-party tile providers like OpenStreetMap. Failing to provide attribution may violate the provider's terms of use, so always ensure this text is present and visible. Giving credit also helps users know the source of the map data, which is important for transparency and trust.