Sunlight is a part of the electromagnetic spectrum. There are also parts of the electromagnetic spectrum that are less familiar to many of us. Some have more energy and some have less. From highest to lowest energy levels, these sources from the Sun include gamma rays, x-rays, ultraviolet rays, visible light, infrared rays, and radio waves (see graphic below). Microwaves are a subset of radio waves.
Energy is transported in waves. Light is made of discrete packets of energy called photons that travel at the speed of light until they come into contact with other matter. Photons have no mass, but they do have momentum. Likewise, energy from the electromagnetic spectrum has both particle-like and wave-like properties. Electromagnetic waves are formed by the vibrations of electric and magnetic fields. These fields are perpendicular to one another in the direction the wave is traveling.
The number of crests that pass a given point within one second is described as the frequency of the wave and is measured in Hertz (Hz). Electromagnetic waves have crests and troughs with the distance between crests called the wavelength. Wavelength is measured as a unit of distance such as mm, cm, nanometer, micrometer, etc.
Images Source: NASA