Existentialism is a philosophical movement that emphasizes individual existence and freedom and responsibility. It became popular after World War II as a way for humans to assert individuality. Major existentialist thinkers include Soren Kierkegaard, Jean-Paul Sartre, and Albert Camus. Existentialism focuses on the conditions of human existence like emotions, actions, and the search for meaning or purpose in life. Existentialists believe that humans have free will and create their own values and identities through their choices and actions for which they are fully responsible.