How can one protect access to sensitive files in PHP applications using htaccess?

To protect access to sensitive files in PHP applications using htaccess, you can create a .htaccess file in the directory where the sensitive files are located. In the .htaccess file, you can use the "Deny from all" directive to block access to all users except for specific IP addresses or ranges that you trust.

# .htaccess file
Deny from all
Allow from 123.456.789.0
Allow from 987.654.321.0