Electromagnetic waves have both electrical and magnetic fields. The dual nature of electromagnetic waves is, there thought to have the traits of particles and waves. That's how they can travel through a vacuum and a medium.
An electromagnetic wave is an energy wave that has both a magnetic field and an electrical field. thats why they have dual nature They have different frequencies and wavelengths and span from Gamma rays to Radio waves.
These travel though both medium and vacuum. They also behave like both waves and particles.
