system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does 3G/4G get the internet to my phone?
gpt
These people suck at explaining this.

Radio is just flashing light. You can stand on a mountain with a flashlight and your friend can stand on the bottom of that mountain also with a flashlight. If you both know, say, Morse code, then you can communicate with each other just using the flashlight, right?

That's all a radio tower and your phone do, except not with the visible light spectrum. They use the radio spectrum instead - which is the exact same as visible light, it's just a different color (that color is called "radio" and it's invisible). But it's really just Morse code and two flashlights flashing at each other.

Radio is a cool color because it can go through walls and cars and other stuff, which is why you don't always have to have a *direct* view of the radio tower.

NOTE: It's not *actually* Morse code. It's binary (as mentioned below) that is made up of 1's and 0's. If you string together a bunch of 1's and 0's, you can make up your own language (like dots and dashes for Morse). This all happens so quickly that even if we could see the color radio, we wouldn't be able to tell it was flashing at all. Also, it "flashes" not in on-off but FM radios (frequency modulation) flash "high frequency" and "low frequency." So it flashes between two shades of radio. AM radios (amplitude modulation) flash "high amplitude" and "low amplitude"." So it flashes between two brightnesses of radio.

**TL;DR: The tower is a flashlight, your phone is a flashlight. They flash a color at each other called "radio" that's invisible to us but visible to each of them and can travel through walls.**