The word extremism means "deviation", i.e. "deviation from the center, departure from the established place". This concept is reflected in the fact that individuals or groups within the society do not recognize the general order and act only with their own opinion. The closest synonym of the word "extremism" is radicalism. And terrorism is the result of that extremism.

Source : https://www.gov.kz/memleket/entities/zhetysu-sarkan-ekiasha/press/news/details/963113?lang=kk