Radio waves are a type of electromagnetic radiation with the lowest frequency and longest wavelength. The frequency range of a radio wave is 3x10^11 Hz and lower. Radio waves are usually used for communication systems, like a radio or a TV satellite. Radio waves are not dangerous because of their low frequency.
Microwaves are a form of electromagnetic radiation that have a frequency range in between radio and infrared waves. The frequency range of radio waves is 3x10^11 - 10^13 Hz. Microwaves are most commonly used to heat food, but can also be used in communication and radar systems. Like radio waves, microwaves are not proven to be harmful.
Infrared waves are the most common form of electromagnetic radiation. These waves are invisible but are felt as heat. The frequency range of infrared waves is 1x10^13 - 4x10^14 Hz. Infrared waves are used for TV remotes and in night-vision goggles. Infrared radiation is naturally occuring in the atmosphere and is not dangerous in moderate amounts.
Visible Light Waves
Visible light is the type of electromagnetic radiation that allows you to see. The colors that we see come from the visible light spectrum. The frequency range of visible light is 4x10^14 - 7.5x10^14 Hz. Visible light is used for lights, telescopes, and is responsible for anything visible to the human eye. Visible light is not dangerous unless your eyes are exposed to extreme amounts.
Ultraviolet waves are the form of electromagnetic radiation that comes from the sun. The frequency range for UV radiation is 10^15 - 10^17 Hz. UV radiation is what gives you a sun tan or a sun burn. UV radiation can also be captured and converted into energy, commonly by the use of solar panels. UV rays can also be used to kill bacteria. UV rays are potentially dangerous, though, as ailments such as skin cancer could result from over exposure.
X-Rays are a high-frequency type of electromagnetic radiation, that are able to penetrate the skin. The frequency range of X-rays are 10^17 - 10^20 Hz. X-rays are commonly used for medical images, cancer treatments, and in airport security scanners. High amounts of x-ray radiation are dangerous and cancer-causing.
Gamma rays have the highest frequency and are more powerful than all other types of electromagnetic waves. Their frequency range is 10^20 - 10^24 Hz. Gamma rays can penetrate through paper(skin), aluminum, and lead. Only a lead/concrete mixture can stop gamma rays. Gamma rays are extremely dangerous. Gamma rays are often used to kill cancer, treat other medical conditions, or produce medical images. Gamma rays are emitted by the nucleus of a radioactive atom.