How does SELinux contribute to 'errno 14 http error 403 - forbidden' on CentOS 7, and how can I troubleshoot it?

SELinux (Security-Enhanced Linux) can block access to files and directories if the security contexts are not properly configured. Use `ls -Z` to view the SELinux context of files and directories. Use `chcon` to modify the context if needed. Alternatively, you can temporarily disable SELinux using `setenforce 0` (then re-enable with `setenforce 1`) to see if it resolves the issue; if it does, investigate SELinux policies further.