Simple Mapping servername to directory:

NameVirtualHost *
<VirtualHost *>
  ServerAdmin webmaster@localhost
  DocumentRoot /var/www/mydir
  ServerName host.domain.com
  ServerAlias host2.domain.com host3.domain.com
  CustomLog /var/log/apache2/host-access_log common
  ErrorLog /var/log/apache2/host-error.log
  Alias /short /long/path/short
</VirtualHost>


Redirection:

NameVirtualHost *
<VirtualHost *>
  ServerName host.domain.com
  RedirectPermanent / http://host.domain.com:8080/
</VirtualHost>