The part of electromagnetic spectrum, defined as radio and microwaves, can be further divided into eight ranges, called bands. These bands are rated from very low frequency (VLF) to Extremely High frequency (EHF)
Very Low Frequency :: These waves propagate as surface waves, usually through air, sometimes through water. VLF may be affected by atmospheric noise. VLF waves are usually used for long range radio navigation and submarine communication.
Low Frequency :: these waves propagate as surface waves. Attenuation is higher during daytime. These waves are usually used for long range radio navigation or navigational locatiors.
Middle Frequency :: These waves rely on line-of sight antennas to increase and control absorption problems. These waves are used for AM radio, radio direction finding and emergency frequencies.
High Frequency :: these waves are used for amature radio, citizen’s band radio, international broadcasting, military communication, telephone and telegraph.
Very High Frequency :: these waves use line-of-sight propagation and are used for VHF television, FM radio, aircraft AM radio and aircraft navigation.
Ultra High Frequency :: these waves use line-of sight propagation and are used for television, mobile phone, cellular radio, paging and microwave links.
Super High Frequency :: these waves are transmitted either line-of-sight or into the space. They are used for terrestrial and satellite microwave and radar communication.
Extremely High Frequency :: These waves are transmitted into space and are used for radar, satellite and experimental communication.