||Well, let's face it. Sometimes, you might be confronted to a sore loser, who, having found the location of your admin folder, will try to find a login and a password to hack your website.
A sore loser, or an evil fellow, I guess.
IPLock work this way : if someone fails too many times to log in your website, his IP adress will be added to a ban list.
Even if he eventually finds a proper login/password pair, well : he's not ever gonna know, because as his IP is banned, he won't be able to log in.