How submarine cables are the global backbone of the internet

Phones have it. Homes have it. Even televisions, offices and entire cities have it. Yet even as more devices depend on Wi-fi, there's a fact about the internet that few of us truly appreciate. The web is not wireless.

It's not even close to being anything other than a hard, painstakingly constructed physical network. A whopping 99 per cent of international data is transmitted by huge submarine communications cables dragged along the bottoms of oceans. When you're online, your data is coming through these cables.

While satellites beam TV around the world, we all embrace the cloud, and Wi-fi spreads through society in ever more unexpected ways, it's actually the humble fibre-optic cable that makes technology tick.

Science fiction author Neal Stephenson has compared earth to a computer motherboard, and it's not hard to see why that analogy makes sense; there are more than almost 300 separate cable systems, each stretching thousands of kilometres between continents.

"Submarine cables are absolutely critical to supporting the internet, carrying virtually all traffic back and forth across the world," says Kaveh Ranjbar, chief information officer at RIPE NCC, one of the world's five regional registries that help ensure the smooth running of the internet. "Their importance means that there are a lot of them, which in turn means the internet has redundancies in place in the event one section does get damaged."