Extremism (represented on both sides of the political spectrum) is an ideology (particularly in politics or religion), considered to be far outside the mainstream attitudes of a society or to violate common moral standards. Extremism can take many forms, including political, religious, and economic.
Extremists are usually contrasted with centrists or moderates. For example, in contemporary discussions in Western countries of Islam or of Islamic political movements, the distinction between extremist and moderate Muslims is typically stressed.
Political agendas perceived as extremist often include those from the far left or far right, as well as radicalism, reactionism, fundamentalism, and fanaticism.
The term "extremism" is usually pejorative, but it is sometimes used in a purely descriptive sense, referring simply to a viewpoint that is inconsistent with existing norms, rather than implying that the extremist position constitutes a threat (to the society, government, mainstream morality, etc.).