Signals can be sent around the world useing layers of the earth's ionosphere or beamed from point to point. Repeaters from buildings or mountaintops can send signals to cars or base stations. Orbiting satelites that hams built are used to achieve communication around the world. Others use computers. Some bounce their signals of the moon even see and talk to the astronauts high above the earth.
Possibilities are almost unlimited.
Amateur radio has world support by many governments. Skilled radio operaters use ham radio in time of war and public service such as emergencies, Natural disasters floods,earthquakes, tornadoes, hurricanes and typhoons. Fairfield Skywarn is a National Weather Service national program of trained volunteer severe weather spotters. Skywarn volunteers support their local community and government by providing the NWS with timely and accurate severe weather reports. Local Skywarn Nets Field Day is just one of many public service type activities held every year in June.