The map in Breath of the Wild is initially blank. You reveal sections of it by activating Sheikah Towers. Once a tower is activated, the surrounding area's topography is added to your map, along with points of interest. You can place pins and stamps on the map to mark important locations.
Fast travel is available to any activated Sheikah Tower or Shrine. Simply open your map, select the desired location, and confirm. This saves a lot of travel time, especially when moving between distant regions. Remember to activate every tower and shrine you encounter.