By default, the URL you use to log into your dashboard is either wp-login.php or wp-admin, added after your site’s main URL. For instance, YOURSITE.com/wp-login.php
And guess what, those two are also the most accessed URLs by hackers who want to get into your database. If you change that URL, you reduce the chances of finding yourself in trouble. Guessing a custom login URL is way harder for hackers.
The iThemes Security plugin does this trick. For instance, your login URL can turn into something like YOURSITE.com/I_like_my_security. This is one of those WordPress security tips that’s very simple to do.