When it comes to religion, the most popular views are monotheism & polytheism. They aren't all the same. Each religion has its strengths and weaknesses. One of the most important differences is the way that each religion views the world. Monotheism tends be more peaceful, and everyone can worship the same god. This helps to avoid conflicts among different civilizations.
Mythology
The difference in monotheistic and multitheistic mythologies doesn't lie in the nature or representation of the gods. Polytheistic mythology views the gods as the product of long-term interactions between the gods.
In ancient Greece, there were twelve Olympian gods, including Zeus and Hera. Demeter, Apollo and Artemis were also gods. Each served a different purpose, including sustenance. Exceptions were made, however, like Hades, who lived underworld.
Morality
Monotheistic and polytheistic societies have different views on morality. While monotheism tends to favor absolute values, polytheism allows for relative morality. These two approaches are very distinct, but they both emphasize the importance of individual accountability.
Monotheistic systems usually elevate one god to a supreme role. They treat the other gods only as manifestations this supreme god. They then become essentially monotheistic.
Religion
One can choose to believe in monotheism, or polytheism. Monotheists believe in the existence of a single, divine creator. Polytheists believe that there are multiple deities. Although each side claims to be right on a particular point, they disagree on what constitutes a true religion.
Polytheism was the source of monotheism. However, it is not clear why. Monotheism is a result of one of two processes, according to modern religious philosophers.