system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Out of the tons of radio signals that are constantly around us all the time, how does my cell phone know exactly which one(s) to "listen" to when I'm calling someone?

Basically, how is the phone able to filter out all of the other "noise" that must come from the hundreds, or even thousands, of other radio signals around us to give me EXACTLY what I want to hear, with zero interference?
gpt
There are electronic devices that are called "filters" that block out certain radio frequencies.  It's like how an FM radio works; only the station you want is allowed through.

The cell phone companies basically buy the right to exclusively use certain frequencies.  (Different frequencies are like different colors.)  One company might be allowed to use one frequency, and another company uses another frequency.

Your cell phone is programmed by your cell phone company to only look at the frequencies they've purchased.

Now, you have to share that frequency with every other customer of that cell phone company.  One way they do this is called TDMA which basically means everyone who is on a call for a particular cell phone tower gets a small amount of time to send/receive, and they all take turns.  The amount of time is so small, and the turns change so quickly that you don't even notice.  It's like how a cartoon might have something like 60 frames per second, and they flip so fast that you can't tell that it's not a continuous image.

Another method is called CDMA, but that uses complex math and these things called orthogonal codes.