An .htaccess file is a text file which includes directives that tell a web server how to operate in particular situations. It needs to be placed into the folder in which these directives should be executed. Loads of script-driven apps use this sort of a file to perform properly - WordPress and Joomla, for example. You can use such a file with personalized content too and do a lot of things - block an IP address, an entire network or specific Internet sites from accessing your site, set custom error pages that shall be displayed rather than the server-generated ones in case a visitor encounters some error on the website, redirect a domain or a subdomain to another web address, create a password-protected area plus more. With an .htaccess file, you'll have far better control over your web presence.