A radio service authorized by the government in the form of an issued license. This entitles one to use specific frequency bands for 2-way communication. There are more than 800,000 Ham Radio Operators in the US, and more than 3 Million world wide. Many modes are available. Morse Code, AM (voice), FM (Voice), SSB (Voice), PSK31 (Digital), SSTV, ATV, FKSK, Fax, AMTOR, PACTOR, CLOVER, ect. Up to 1500 Watts of Power on some bands.
From the U.S., I was talking to a Ham Radio friend in Argintena on 20 Meters.
A FCC licensed radio service to further the radio arts, and promoted good will to others. Amtateur by definition, means to do something without financial interest. This hobby / service is used to same many lives during disasters such as hurricanes, earthquakes, floods, weather spotting, and the like. It has the ability to talk to people around the world with simple equipment, and without need of infrastructure.
Amateur Radio is a lot of fun to talk to people far away.