An .htaccess file is a text file that includes directives which tell a web server how to operate in specific cases. It must be placed in the folder in which these directives should be executed. Numerous script-driven applications use such a file to work efficiently - WordPress and Joomla, for example. You can use this sort of a file with personalized content as well and do a wide range of things - block an IP address, a whole network or certain sites from accessing your site, set customized error pages that will be displayed rather than the server-generated ones in case a visitor encounters some error on the site, redirect a domain or a subdomain to another web address, set up a password-protected area plus more. With an .htaccess file, you shall have more effective control over your world-wide web presence.