Earlier quoted context omitted.
It's possible in Chrome and Firefox (and I assume other browsers, though can't say for sure) to add search shortcuts for other websites. If I know I want the wikipedia link, rather than searching google for the thing, I type "wp ", and it takes me either directly to the wikipedia page, or to the search results. I think the default is the domain followed by a space, so "wikipedia.org ", but that can be changed.
this has always befuddled me. why use google at all to search a specific site rather than searching on the site directly? why give google the traffic? because lazy/convenience of google being the default page for new browsers and/or google the default search associated with the location bar?
Or use to. Now the quality and quantity of results forces site owners to implement their own search or use third parties.