This page in a nutshell: Redirects aid navigation and searching by allowing a page to be reached under alternative titles.
A redirect is a page which has no content itself, but sends the reader to another article, section of an article, or page, usually from an alternative title. For example, if you type "UK" in the search box, or follow the wikilink UK, you will be taken to the article United Kingdom, with a note at the top of the page: "(Redirected from UK)". This is because the page UK contains the wikitext #REDIRECT [[United Kingdom]], which defines it as a redirect page and indicates the target article. It is also possible to redirect to a specific section of the target page, using the #REDIRECT [[Page name#Section title]] syntax.