What role does the .htaccess file play in causing a 403 error?

The .htaccess file controls how your Apache web server works. Incorrect directives within this file, such as improper `Deny from` or `Order` rules, can easily cause 403 errors. A common fix is to rename the .htaccess file (e.g., to .htaccess_old) to see if that resolves the issue, then rebuild it carefully.