Amateur Radio (Ham Radio) is the use of certain radio frequency spectra for the purposes of non commercial exchange of messages, wireless experimentation, self-training, recreational and educational purposes and for emergency communications.  The term “amateur” is used to specify an authorized person interested in radioelectric practice with an aim being entirely personal. This person does not use ham radio for monetary purposes. The term is also used to differentiate it from commercial broadcasting, Public Safety Announcement (PSA), or professional two-way radio services like those use in police forces, maritime aviation and etc.  National governments regulate technical and operation characteristics of transmissions and issue individual station licenses with an identifying call sign. Prospective amateur operators are tested for key concepts in electronics and the use of the host government’s regulations. Amateur Radio use a variety of voice, text, image and data communication modes and have access to frequency allocation though the RF spectrum to communicate across a city, country, region, continent or even into space.