What it is: Fundamentalism was a Christian religious movement which developed in America in the early 1920s. Its followers believe in strictly obeying what they regard as the rules of their Christian faith. This includes accepting that everything written in scripture (the Bible) is literally true. In the 1950s, Muslims who followed a strict interpretation of their scripture, the Koran, also became known as 'fundamentalist'. The word has also been used to refer to anyone who accepts (and tries to live by) a doctrine without questioning its source or the way it is taught.
What it means: By the end of the 20th century 'Islamic fundamentalism' had become associated with terrorist and other groups fighting for the creation of exclusively Muslim states and regions. The Koran calls for jihad, or holy war, against non-believers. For many Muslims this means a spiritual struggle that goes with commitment to their faith. Fundamentalist Muslims, however, see it as a justification for armed aggression against non-Muslims. Non-Islamic countries think it can justify an armed response. Despite the peaceful ideals of (New Testament) Christianity and Islam, both have been associated for many centuries with wars against 'unbelievers'. Fundamentalism has also sometimes formed dangerous alliances with nationalism, leading to violence, aggression, and armed conflict.
Think about it: 'Everyone has the right to freedom of thought, conscience and religion'. (The Universal Declaration of Human Rights) 'Communities separated into "them" and "us", religion became the marker of identity, borders were suddenly drawn.' (An observer in India, 1997) 'The religious political parties have no intention of letting people think or make up their own minds.' (An observer in Pakistan in 1999)