Federación Digital EA

Amateur radio, also called Ham radio, is a hobby and a public service enjoyed by about 6 million people throughout the world. An amateur radio operator, also known as a ham or radio amateur, uses advanced radio equipment to communicate with other radio amateurs for public service, recreation and self-training. (Wikipedia)

This is the official definition of Amateur radio by ITU:

«A radiocommunication service for the purpose of self-training, intercommunication and technical investigations carried out by amateurs, that is, by duly authorized persons interested in radio technique solely with a personal aim and without pecuniary interest».

To use amateur radio bands you need an authorization that you can obtain after an examination. In Spain this is the procedure to follow.