What TYPE of energy is used in a radio?

A radio is built to catch some of the electromagnetic energy sailing past its

antenna, and use that small trace of energy to control electric circuits in the

radio, in order to create a much more powerful copy of the electromagnetic

waves that it caught. When that's been done inside the radio, it'll eventually

use the powerful copy to wiggle the paper cone of a speaker or the diaphragms

in a pair of earbuds, in order to convert some of the electrical energy into sound

energy that can be detected by human ears.

By changing just one step at the end of the process, the powerful copy can be

used to manipulate the motion of the spot on a fluorescent, LCD, or plasma

screen, in order to convert some of the electrical energy into light energy that

can be detected by human eyes.