Cade Metz, writing for Wired:
Rather than relying on street addresses or postal codes — which may get you only so close to your destination — What3Words lets you pinpoint a location and pinpoint it in way that doesn’t require, say, a seemingly endless string of GPS coordinates. “There’s an ease to words,” Sheldrick says. “It’s a way of encoding a huge number into something memorable.”
It looks something like this: fetches.almost.overtime, which is the three word coordinate for the Eiffel Tower (compared with its address, 5 ave Anatole 75007 Paris).
In a way, this is a very old idea. For a millennia, people have given names to specific places, the numbers of which varied according to an area’s population density. The only difference is that What3Words divides the world into equal-sized squares. It’s more regular, less flexible, and less organic, but it works well with computers. It’s also being rolled out in other languages.
The only downside is that, unlike addresses, What3Words isn’t hierarchical. In other words, I can’t first navigate my way to a city, then find the street, then follow the addresses up or down until I arrive at my destination. Using What3Words requires a connected device, something that addresses don’t.