Electromagnetic waves are transverse waves, so particles move perpendicular to the direction of energy transfer. Their oscillations are changes in electrical and magnetic fields which are in phase with each other and vibrate at 90° from each other.
Electromagnetic waves run along a spectrum of different wavelengths. All of these waves travel at the same speed in a vacuum, but the different frequencies and wavelengths means that each of the various waves on the spectrum have different properties.
The different properties of electromagnetic waves along the EM Spectrum mean that each type of wave can be used for different purposes. High energy waves are often used in medicine such as x-ray imaging and chemotherapy, whereas waves with long wavelengths tend to be used in communication. It is important to know a few purposes for each type of wave.
Exposure to certain types of electromagnetic radiation can cause a lot of damage to the body. The higher the frequency of the waves, the more damage they can cause to living things. UV, x-rays and gamma rays are types of ionising radiation – ionisation can have very hazardous effects on the body.