Monotheism is the worship of a single divine being. The history of monotheism is the history of individual cultures adapting their beliefs in a changing world, often from polytheism to henotheism to monotheism. Monotheistic faiths are represented all over the world in a variety of different religions and sects.
Monotheism is the belief in one god. Polytheism, on the other hand, is the belief in more than one god. Examples of polytheistic religions are: Hinduism, the ancient Greek religion, and the religion of the Vikings.