Vector skin, simplified search box. Note that an empty Search displays "Search".
Monobook skin, search box format.
Wikipedia has its own search engine, with its search box on every page. The search box will go to a given page name, but there are three ways to go to the search results page instead.
If you activate the magnifying-glass icon (or the Search button) from an empty search box, you'll go to an empty search results page.
If you start any query with the tilde character, it always generates search results, ~page name.
At an empty Search display, there are filtering options for:
Content pages – Search in (Article)
Multimedia – Search for files
Everything – Search of all content (including talk pages)