All Drupal core modules, themes, scripts, libraries, includes, and text files have been moved to a "/core" subdirectory of the Drupal repository with the exception of these directories:
This results in some common paths such as "update.php", "cron.php", and "install.php" now being located at "core/update.php", "core/cron.php", and "core/install.php". However a redirect has been added to the core .htaccess file to make it so that these paths will automatically redirect to their new locations for most users familiar with the old paths.
Placement of non-core modules and themes
- Following this change, contributed and custom modules can now be placed in the
modules/folder in the root of the Drupal installation, and contributed and custom themes can be placed in the similar
- This differs from Drupal 7 and earlier, where these folders were used for core modules and themes.
sites/all/themes/folders can also still be used, as can site-specific subdirectories.
core/themes/directories should never be used for contributed or custom modules.