Over the past several years, there continues to be development of different modes for Hams to communicate with on the Ham Bands. Some are as much as 150 years old eg. in Morse code and others are somewhat newer, up to and including the newest digital modes only months old.
|Single Side Band (Upper or Lower) Voice
|Frequency Modulation Voice
|Usually Computer Generated (30+ Types)
For further information on Where to Listen on the various Operating Modes, visit your favorite search engine, for example http://www.google.com and enter a search for "Ham Band Allocations" or "Ham Band Modes of Operation".