What is a radio frequency (RF) electromagnetic field?

Part of the electromagnetic spectrum extending from 3 kHz frequency to 300 GHz is referred as radio frequency (RF). Television and radio transmitters (including base stations) and microwaves, mobile telephones, and radars produce radio frequency fields. These fields are used to transmit information and form the basis of telecommunications as well as radio and television broadcasting all over the world. Many home devices also transmit EMF at radio frequencies such as cordless phones, baby monitors and radio-controlled toys.