What is waving in an electromagnetic wave?

The electric field and the magnetic field

Explanation:

An electromagnetic wave consists of oscillations of an electric field and a magnetic field, oscillating perpendicularly to each other. The oscillation of the two fields also occur on a plane which is perpendicular to the direction of the propagation of the wave itself (due to this feature, this kind of waves are called transverse waves).

One of the main difference between electromagnetic waves and other waves is that electromagnetic waves are the only one that can travel through a vacuum, since they do not need a medium to propagate (such as, for example, sound waves).

The speed of the electromagnetic waves is constant in vacuum and its value is called speed of light, equal to:

igneous rocks also form where plates converge. the subducting plate melts as it sinks into the crust of the earth, and the melt rises into the overriding plate forming volcanoes. metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. -woods