Believing in and faithfully following the fundamentals of a religion is fundamentalism. By definition true Christians, true Jews and true Muslims are all fundamentalists.

Unfortunately, a lot of people have been systematically trying to demonize Islam. The Western media has been, for some reason, very supportive of those people by simply equating the word fundamentalism of Muslims to the word terrorism.
Strangely, the fundamentalism of the Jews and the Christians is seen as a positive trait and reported accordingly.

Terrorism targets innocent people to instill fear. Islam forbids killing of innocent people even if they are defending themselves.
Islam equates killing of a person to killing an entire race and considers that as one of the worst crimes.
Suicide is also forbidden in Islam.

A true fundamentalist Muslim or a practicing Muslim can never be a terrorist or approve of terrorism because Islam is the most humane and rational religion.