While many think of Windows 8.1 as a massive collection of small fixes, this release does in fact offer two major new features. One is its deep SkyDrive integration, which I write about elsewhere. But the other is deep Bing integration, which results in a truly innovative and useful new feature called Smart Search.

Smart Search isn’t a name or brand you’ll see anywhere in Windows. This is what Microsoft calls the feature internally. Essentially, it’s the latest version of Windows Search, which was exposed by the Search charm in Windows 8, but is now available from a variety of places in Windows 8.1, including special modes for the desktop and in-app search icons that trigger only a contextual, app-based search.

Put simply, Smart Search is Bing integration with Windows Search. Instead of the dumb app, settings, and file search differentiation in Windows 8/RT, Smart Search now provides a single interface that combines local searches with web searches. It sounds dumb until you see it. Because the results are often beautiful indeed. More to the point, the results are also useful.

Consider a typical search. I love the city of Paris, for example, and if I search for Paris in Windows 8.1, I see local results—documents, photos and music in this case—and then the start of a really impressive web search “hero” interface, with deep Bing-based results from the web, the Weather, Travel and Maps app (in this case), and more.

For example, if you tap on the Explore link, the Travel app opens.

Back in Smart Search, you can scroll over and there are more web-based results.

Tap on Images of Paris, and a nice image search experience appears.

There are some amazing options here. You can filter by size, color, type, layout or people from the app bar. So for example, if you want to see only photos of Paris that are purplish in color, you can do so. Pretty amazing.

Smart Search is for more than just places, of course. There are hero results for people, too.

Not a fan of Smart Search? You can disable it. But you can also filter the search right from the Search pane and only see what you’re looking for.