How can .htaccess be used to secure a PHP project, and what limitations does it have in terms of data validation and security measures?

To secure a PHP project using .htaccess, you can restrict access to certain directories or files, prevent directory listing, and set up custom error pages. However, .htaccess has limitations in terms of data validation and security measures as it primarily focuses on server configurations and access control, rather than input validation or sanitization. ```apache # Disable directory browsing Options -Indexes # Restrict access to .htaccess file <Files .htaccess> Order allow,deny Deny from all </Files> # Custom error pages ErrorDocument 404 /errors/404.php ```