Place downloaded and custom themes that modify your site's appearance in this
directory to ensure clean separation from Drupal core and to facilitate safe,
self-contained code updates. Contributed themes from the Drupal community may
be downloaded at http://drupal.org/project/themes.

It is safe to organize themes into subdirectories and is recommended to use
Drupal's sub-theme functionality to ensure easy maintenance and upgrades.

In multisite configuration, themes found in this directory are available to
all sites. In addition to this directory, shared common themes may also be kept
in the sites/all/themes directory and will take precedence over themes in this
directory. Alternatively, the sites/your_site_name/themes directory pattern may
be used to restrict themes to a specific site instance.

Refer to the "Appearance" section of the README.txt in the Drupal root
directory for further information on theming.