[andrewljohnson]

In GIS world, a vector tile is a chunk of geographic data (the vectors) limited to a geographic region (the tile boundaries which fit into the projected checkerboard of your map).

You use a vector tile instead of a png or jpeg tile because you don’t want an image representation of the data, you want the raw “vector” data so you can style it, search it, and do other things with it on client devices.