uBlock Origin

An efficient adblocker. It uses low processor power and low memory.
How efficient is uBlock Origin: https://github.com/gorhill/uBlock/wiki/uBlock-vs.-ABP:-efficiency-compared
This tool gives you the opportunity to apply and load thousands of filters, more then every other competitive adblocker. Regarding internetcookies it uses hpHosts’s tracking servers. It’s open-source with public licence (GPLv3).
Even though Firefox blocks trackers by default, some users prefer ad-blockers. uBlock Origin is an efficient blocker that can load and enforce thousands of more filters than other popular blockers out there and uses limited memory. – Sabarinath @ techlog360.com
More information on https://en.wikipedia.org/wiki/UBlock