What is the difference between healing and fortifying a unit?
Healing a unit will replenish strength to units that have suffered a damage in health, whereas fortifying a unit, unlike in Civ3, will not heal the unit. It will provide a defensive bonus of 5% a turn, with a maximum of 25% to that unit. Keep in mind that when healing units, it is quicker inside your territory than neutral territory (and that is faster than enemy territory); units in cities also heal faster. Promotions will heal half of a unit’s damage when they are selected. For more info about healing, see this article by PieceOfMind.
