Final answer:
Monotheism is the belief in a single god. It is a basic belief in many religions, including Judaism, Christianity, and Islam.
Step-by-step explanation:
Monotheism is the belief in a single god, as opposed to polytheism, which is the belief in multiple gods. It is a basic belief in many religions, including Judaism, Christianity, and Islam. Monotheistic religions believe that there is one supreme deity who is all-powerful, all-knowing, and eternal. Example of monotheistic religions are Islam, which believes in one God, Allah, and that Muhammad was his prophet; and Judaism, which believes in one God who made the universes at the beginning of time and will end the universe.