Redirects are a wiki tool for consolidating many names for a thing under one page; for example, mod, moderator, and Game Moderator may all point at the same page, game moderator. They avoid the need to keep multiple copies of information up-to-date, and enable searches to work better by redirecting natural search terms to the actual page that covers their topic.
Redirects can also be categorized if it makes sense to do so; for instance, a redirect for the special case of Godfather Mason may be in Category:Scum Roles, while the target article, Mason, is a pro-town role.
Redirects only work once; to avoid infinite loops, a double redirect will simply stall out at the first target, and display the next target on that page. These can be fixed by going to Special:DoubleRedirects and changing the first target to point at the final/actual page.