Every browser has some kind of adblocking facility built into it, Firefox web browser is no exception. But the browsers (or computers itself) are not smart enough to recognise advertisements from content.
The solution has always been using community contributed filters expressed in regex(Regular Expressions) that match the ad’s.
Adblock Filterset.G Updater is the Firefox extension that automatically updates “Filterset.G.”: http://www.pierceive.com/filtersetg/ . It works with both older Adblock or Adblock Plus extensions.
The user can also write personal filters that will persist between filterset upgrades. Also, Adblock Plus has feature to use other EasyList, RU AdList filtersets.