expressjs.com/en/api/res-redirect.jade

section
  h3(id='res.redirect') res.redirect([status], url)
  p.
    Redirect to the given <code>url</code> with optional <code>statua</code> code
    defaulting to 302 "Found".

  +js.
    res.redirect('/foo/bar');
    res.redirect('http://example.com');
    res.redirect(301, 'http://example.com');
    res.redirect('../login');

  p.
    Express supports a few forms of redirection, first being
    a fully qualified URI for redirecting to a different site:

  +js.
    res.redirect('http://google.com');

  p.
    The second form is the pathname-relative redirect, for example
    if you were on <code>http://example.com/admin/post/new</code>, the 
    following redirect to <code>/admin</code> would land you at <code>http://example.com/admin</code>:

  +js.
    res.redirect('/admin');

  p.
    This next redirect is relative to the <code>mount</code> point of the application. For example
    if you have a blog application mounted at <code>/blog</code>, ideally it has no knowledge of
    where it was mounted, so where a redirect of <code>/admin/post/new</code> would simply give you
    <code>http://example.com/admin/post/new</code>, the following mount-relative redirect would give
    you <code>http://example.com/blog/admin/post/new</code>:

  +js.
    res.redirect('admin/post/new');

  p.
    Pathname relative redirects are also possible. If you were
    on <code>http://example.com/admin/post/new</code>, the following redirect
    would land you at <code>http//example.com/admin/post</code>:

  +js.
    res.redirect('..');

  p.
    The final special-case is a <code>back</code> redirect, redirecting back to
    the Referer (or Referrer), defaulting to <code>/</code> when missing.

  +js.
    res.redirect('back');