The application network riding on a general-purpose relevancy engine does things like quickly and efficiently match what you want or would want if you knew what you wanted (I know that last bit sounds a little silly on its face) with knowledge, goods, services, and so forth. For example, if you expressed a vague desire for transportation, the application network that rides on the engine would bring up all available and relevant transportation options and their merits and drawbacks — buses, trains, cars, bicycles, skateboards, electric scooters, whatever. Presumably, if you wanted a quick ride to the grocery store, you'd be matched with that nice high-reputation college student a couple of blocks away who's going out to meet friends anyway but who would be willing to drop by and give you a ride over to the grocery store in return for a few bucks for gas money. It does sound like Uber and so forth but is far more flexible, complete with automatic deep-network background screening to keep out the lunatics and skeevy drug addicts and perhaps add automatic, low-cost micro-trip insurance to cover potential liability for even such a short journey.

Alternatively, of course, you might see a list of known good cars for sale from local or out-of-state high-reputation sellers along with suggestions to observe standard precautions such as having a prospective used car checked out by a reputable local mechanic, the best of whom are listed right there for you to contact online. None of this stuff is new under the sun, but the relevancy engine helps automate and facilitate transactions to a much greater degree than exists today. In this example, it brings up absolutely everything you should know about buying a car in a moderated form that doesn't overwhelm you with information, complete with quick links to ad-hoc assistants (shades of TaskRabbit and similar existing services) who're willing to help out with making sure you don't get ripped off by going with you to the seller. Videos come up that show a specific car model in operation, and video and textual chat rooms and forums swarm with kibitzers who make snarky or useful comments on your prospective purchase and problems you might or might not encounter with it — it eats oil, perhaps, or the default steering wheel is kind of stiff.

Yeah, that came across as chaotic. Can't be helped. The actual operating guides will take up entire books. Anyways, it is to be hoped I didn't mangle that quick and-dirty, limited example application too much! ^_^