Permission Denied and 403 (Forbidden) Response in Apache HTTPD

Issue

• I get "Forbidden" when I access a page in Apache. How can I troubleshoot it?

• While accessing the PDF file from a web site hosted in Apache HTTPD server, I am getting following You don't have permission to access /app/test.pdf on this server message in web browser and following error in ssl_error_log.

  [error] [client 127.0.0.1] (13)Permission denied: file permissions deny server access: /var/www/html/app/test.pdf