A Telecom market analysis company called TeleGeography developed with Huawei Marine Networks an impressive map showing all submarine cables connecting the globe.
The submarine optic-fiber cables connects all the continents, allowing remote locations to interlock; and are responsible for almost all the World Wide Web communication. The cable based communication is extremely cheaper than the one using satellites, and is responsible for almost 99% of the wide-distance Internet connections.
The cabling solution is not only used by the internet, and is not recent either. Brazilian entrepreneurs, like Visconde de Mauá, have been using submarine cables for telegraphic communication with Europe since the nineteenth century.
The video below describes how the this cables are laid in the bottom of the sea.
More information at submarinecablemap.com