The .htaccess file (with a dot at the beginning of the name) is utilized to manage the server within your hosting account. Placing a .htaccess file in the root directory of your account allows you to control the entire account. Additionally, you can create it in any folder of the root directory (except CGI-bin) to manage the content of these folders individually.
Modifications made to .htaccess files take effect immediately and do not necessitate a server restart.