The difference between XYZ and TMS tiles and how to convert between them
Lots of tile-based maps use either the XYZ or TMS scheme. These are the maps that have tiles
/0/0/0.png or something. Sometimes if it's a script, it'll look like
&z=0&y=0&x=0 instead. Anyway, these are usually maps in Spherical Mercator.
Good examples are OpenStreetMap, Google Maps, MapBox, MapQuest, etc. Lots of maps.