Fiber Optic Cables are the things that get you to sites such as youtube or facebook here is an example.
Without these cables we couldn't even load the game pong!(Well we could it would just take a long time) So these are the most important thing for the internet today because without them we would need to go back to the older slower version with the terrible phoneline noise.
Here's an image of a fiber optic cable:
Fiber optics are just tubes of some sort of rubbery substance and inside are glass threads used to move the packets of the website you want in about 0-3 seconds.
A video showing te workings of the internet and WWW
Of course these are the very fabric of loading things to your computer if these never existed we would be wait forever just to load youtube or soundcloud (Top Things for Music and Videos) so we would need to hear and see these in very low quality.
So how have these amazing Cables helped us?