Radios work by transmitting information using radio waves . Radio waves behave like visible light waves —they travel long distances in straight lines.

Imagine you are standing across from a friend in an open field. If you had a flashlight, you could send your friend a code (for example, morse code) by turning your flashlight on and off in a pattern. Your friend would see the flashes of light, and could interpret your message. In this way, they would be using their eyes to capture the signal from the flashlight.

Just like sending signals to a friend over a distance using a flashlight, radio waves can be used to send information. Unlike the light from a flashlight, though, we can’t use our eyes to capture the information from radio waves. Instead, a radio uses an antenna to capture the radio waves sent by the radio broadcaster. The information contained in the waves is then converted into the sound that you hear.

An advantage of radio waves over light waves is that radio waves can pass through most objects, so you can receive the radio waves despite obstacles (or when you are inside).