system
Given the following post, respond as if you're commenting on Reddit:
human
LI5: What exactly is bandwidth and how does an ISP make more of it?
gpt
I'll take this. Edit incoming.

EDIT: If you remember the days of dial-up, your computer was much slower at downloading things from the internet. Much longer ago, information was exchanged slower than that, such as in communications in wires under the ocean.

We communicate digitally with lots of 1s and 0s - on settings and off settings - and bandwidth is how many 1s and 0s we can send at a time through the connection. Higher frequencies can carry more stuff, just like how TV signals can carry more information than radio signals, or how FM (which is a higher frequency) carries stereo sound instead of AM's Mono.

So you can get more bandwidth to your house with a better cable, but you also need a high quality connection, or else more of your 1s and 0s will be spent doing error checks to make sure that the rest of your signals are getting through. More errors = less speed.

Your ISP has to get all of that data (and there's a lot of it) into the internet. That can be tricky if there are distances involved, and it often means laying fiberoptic wires, which carries a large investment cost. To get that money back, the ISP charges more for people that use more bandwidth.