Fiber-optic cable is a critical component of the modern Internet. It allows more data to travel at a single time than conventional copper wiring. That's why Google, Verizon and AT&T all run fiber to your home if you want to get their fastest Internet packages.
Not that copper wiring can't be upgraded to carry a lot more than it currently does. A system called G.fast might let it carry Gigabit Internet - or 1,000 megabits-per-second, which is much higher than the 3 megabits it averages now - starting in 2016. Click here to learn more about this technology.
Still, Gigabit Internet is small potatoes when you're talking about the rise of UltraHD 4K video and billions of new smartphones and tablets poised to go online. To carry that load around the world, you need something faster and that's fiber.
Of course, even fiber has limits. A single fiber is currently limited to a single laser, or carrier, which can only send around 100 gigabits per second.
That's why even the government's exclusive high-speed ESnet network loses steam at 91 gigabits. That's nothing to sneeze at, but it turns out we can do much better.