Frequency modulation

Frequency modulation (FM) is a way to send signals by changing their frequency. To understand how it works, think of a dance music. The volume (loudness) of the music goes up and down, like waves. FM works in a similar way - instead of the volume going up and down, the frequency of the signal goes up and down. It looks like waves going up and down too, only it's the frequency that goes up and down instead of the volume. That's why it's called frequency modulation - because the frequency of the signal is changing (or modulating). FM is used for lots of things, like for radio broadcasts, cell phones, and Wi-Fi.