When you install Drupal, the directory containing Drupal’s core code files is referred to as its docroot, or document root. Not only does the docroot directory contain Drupal’s core code files, but it also includes all your websites’ files and directories.
When you encounter docroot in a documented directory path, substitute
docroot with the actual application path for your environment. If there is
an extended path, such as docroot/sites/all, append /sites/all to the
actual path of docroot.
Docroot on Cloud Platform
If you host your website on Cloud Platform, the docroot is a directory
called /var/www/html/sitename.env/docroot. The directory and its files
are read-only, except for the files stored in the user-uploaded files path
(such as /sites/default/files). You can only send files and changes to
your website’s code files using a version control system (VCS), including
Git.
For more information about files on Cloud Platform, including user-uploaded files, see the Understanding files Cloud Platform help page.