On OpenStreetMap's main site (like [here][1]), there are 6 different layer options to choose from (like Standard, Transport Map, Cycle OSM, etc):
[![enter image description here][2]][2]
 
However, on [OSM's wiki on Tile Servers][3], not all of these layers are available! For example Transport layer is not available.

Doesn't OSM website itself use a tile server to fetch the tiles corresponding to its supported tiles? Where can I find the tile servers for all of these featured layers?


  [1]: https://www.openstreetmap.org/#map=7/52.676/12.019
  [2]: https://i.sstatic.net/SLtHG.jpg
  [3]: https://wiki.openstreetmap.org/wiki/Tiles#Servers