Monotheism is a religion or belief system that involves just one God. Different religions have different numbers and types of gods. Those with no Gods such as Buddhism and Taoism are atheist religions, and Humanism is an atheist philosophy. Those with many Gods are polytheist, including Hinduism, ancient Roman Religions, Wicca, most types of Paganism and old Semite religions. The most famous monotheistic religions are Judaism, Christianity, Islam and Sikhism.
Judaism, Christianity, Islam are called the "Abrahamic religions" because they share the same set of Hebrew stories featuring Abraham, who may have lived in around the 19th century BCE, although some scholars today question his status as a historical figure1. The Bible and the Qur'an contain accounts of Abraham that are "somewhat different"1 and there is no archaeological or genetic evidence that any peoples in the Middle East are descended from such a father-figure. David Leeming in "Jealous Gods & Chosen People: The Mythology of the Middle East"2 calls him a "mythical hero and father"3.
Most monotheistic religions have a god that has certain common characteristics, and it is this type of religion and this type of god that this website is largely about. The typical monotheistic god is Omnipotent (infinitely powerful), omniscient (all-knowing), the supreme creator and First Cause of all existence, benevolent (perfectly and purely good-natured) and personal (it cares about, and communicates with, individual people). More about the assumed character-traits of the monotheistic god: "The Assumptions about God and Creation, of Both Theists and Atheists" by Vexen Crabtree (2014)