While it can do so much more, the core function of Adblock Plus is to block annoying advertisements. The lists are created and maintained by a large online community. These filterlists, are basically an extensive set of rules, which tell Adblock Plus what to block. The so-called filterlists tell the adblocker what to block. Adblockers itself have no functionality, in the sense that they do not block anything until it is 'told' what to do. An adblocker for Chrome or Firefox is an extension (or add-on) to your browser, which adds functionality to your browser so it can filter content.
