system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can millions of people use the ~400 underwater cables for internet simultaneously?

I'm aware each cable is branched into many many smaller cables but surely there still can't be one cable per person so how is the issue of overlapping data signals solved?
gpt
There isn’t one cable per person. Many (many many many) people are taking tiny slices of transmission time in turn.

In addition, if it’s a fiber optic cable, you can run multiple light beams down one fiber and they won’t interfere with each other. 

So one physical cable will contain many individual fibers, each fiber can carry multiple signals, and each signal is time shared between a huge number of individual users.