Final answer:
Polytheism believes in multiple deities, while monotheism believes in one deity.
Step-by-step explanation:
The difference between polytheism and monotheism is that polytheism believes in multiple deities, while monotheism believes in one deity. Polytheistic religions, such as Ancient Greek and Roman religions, have multiple gods with various responsibilities, personalities, and capabilities. Hinduism, for example, is a polytheistic religion with a pantheon of deities. On the other hand, monotheistic religions, like Christianity, Islam, and Judaism, recognize a single supreme God. These religions have billions of followers worldwide.