The various types of electromagnetic radiation are distinguished from each other by their

By their wavelength/frequency

Explanation:

Electromagnetic waves consist of oscillating electric and magnetic fields, that vibrate one perpendicular to each other, and that vibrate perpendicularly to the direction of motion of the wave (for this reason, these waves are called transverse waves).

Electromagnetic waves are also the only type of waves that don't need a medium to propagate, so they can travel through a vacuum as well.

Electromagnetic waves have different properties depending on their wavelength/frequency, and they are classified into 7 different types. From shortest to longest wavelength:

Gamma rays

X-rays

Ultraviolet

Visible light

Infrared

Microwaves

Radio waves

All these waves are invisible to human eye, except for the 'visible light' part of the spectrum.