Airspace means the portion of the atmosphere that controlled by a particular State on its territory and territorial waters or, generally, any specific three-dimensional portion of the atmosphere.
Controlled airspace exists where air traffic control has control over aircraft flying in that airspace.
Uncontrolled airspace is airspace in which air traffic control does not control any aircraft flying in that airspace, although it may act in an advisory manner.
Airspace is divided into areas and zones, including prohibited, danger and restricted areas.
By international law, the area of a country’s sovereign airspace extends for territorial waters to 12 NM (22.2 km) out from a country’s coastline. Airspace not within any country’s territorial limit is considered international. a country may, by international agreement, responsible for controlling parts of international airspace, such as those over the oceans. There is no international agreement on the vertical extent of airspace.