Monotheism or polytheism are the most common views when it comes to religion. But they are not all the same. Each religion has its strengths and weaknesses. The main difference between the religions is how they view the world. Monotheism tends towards peace and allows all to worship the same God. This helps to avoid conflicts among different civilizations.
Mythology
The difference between monotheistic versus polytheistic mythologies rests not so much on the nature of the gods as on how these gods are depicted. The gods in polytheistic mythology are seen as the result of long-term interactions among the gods.
There were twelve Olympian Gods in ancient Greece. Demeter, Apollo and Artemis were also gods. Each of them served a purpose, including the provision of sustenance. However, a few were left out, such Hades, who lived underground.
Morality
Monotheistic and polytheistic societies have different views on morality. Monotheism favors absolute values while polytheism allows you to have relative morality. Both approaches are very different but both stress individual responsibility.
Monotheistic systems typically elevate one god up to a supreme status. Then they treat all other gods as manifestations or the supreme god. They then become essentially monotheistic.
Religion
Monotheism and polytheism are two different approaches to religion. Monotheists believe in the existence of a single, divine creator. Polytheists, however, believe in multiple gods. While each view claims to be correct, the two sides differ on what makes a religious belief true.
The origins of monotheism were polytheism. But the reason for this is still unclear. Modern philosophers of religion have attributed the rise of monotheism to one of two processes.