How are islamism and fundamentalism alike

Islamic fundamentalism has been defined as a movement of Muslims who think back to earlier times and seek to return to the fundamentals of the religion[1] and live similarly to how the prophet Muhammad and his companions lived. Islamic fundamentalists favor "a literal and originalist interpretation" of the primary sources of Islam (the Quran and Sunnah),[2]seek to eliminate (what they perceive to be) "corrupting" non-Islamic influences from every part of their lives[3] and see "Islamic fundamentalism" as a pejorative term used by outsiders for Islamic revivalism and Islamic activism.[4]