Vector tiles are pieces of spatial data in vector form, packaged into pre-defined "tiles" for transfer over the web. This is an emerging method for delivering web maps, combining certain benefits of pre-rendered raster map tiles with vector map data. As with the widely used raster tiled web maps, map data is requested by a client as a set of "tiles" corresponding to square areas of land of a pre-defined size and location. Unlike raster tiled web maps, however, the server returns vector map data, which has been clipped to the boundaries of each tile, instead of a pre-rendered map image. [ref 2]

From a cartographic standpoint, the main benefit is that styling can be applied in the browser itself, allowing much greater flexibility in how data is presented. It is also easier to provide interactivity with map features, as their "raw" vector representation is available to the client's programming environment (typically Javascript in the browser).

There are at present several technological solutions emerging on how to implement vector tiles in web mapping applications [ref 3]. For this research, you will be expected to review these and compare them in terms of "cartographic strengths & weaknesses", i.e. describe how the set-up of each solution will influence the possibilities and challenges from a cartographic point of view.