The term Ash can have different meanings:

  • What remains after a fire. Those things are called debris, and remain after incineration.
  • Volcanic ash, the material ejected by a volcano.
  • Fly ash and bottom ash. What remains after burning coal.
  • Ash trees are trees generally of the genus Fraxinus.
  • European Ash is a species of ash tree
  • Mountain Ash is another tree, generally not in that genus.