A redirect is a way to let a page have multiple names. It is most commonly used to point to subsections or subtopics within a page, so that one can link directly to these subsections/subtopics, and what links here remains an accurate guide to conceptual linkage and topic association. To create a redirect, replace the page content with something like:
- #REDIRECT[[main neutral page name]]
The so-called "pipe trick" is a way to avoid creating redirects, but it is controversial as it encourages proliferation of many phrases to introduce the same article, which are usually idiosyncratic. Many think a few factionally defined redirects are a much better way to deal with pages that have different implications to different people - see anchor text and wiki linking for more on this.