It depends, there are two or three different entities named Satan, that we know of, excluding UPG which is unreliable in things of theory and only holds value if it provides practical use.
The first Satan is the Satan of Judaism which is an angel whose name is Samael. In the Kabbalah, he’s an the ruling Archangel of Geburah (Judgement). The Archangel Samael, the Satan, fulfills the role of a defense attorney, his role is to accuse men before God, he is also the angel that slaughtered the firstborn sons in Egypt.
The Second Satan is the Christian Satan, it more closely follows the Dualistic Zoroastrian teachings about a cosmic war between a Good God (Yahweh/Ahura Mazda) and an Evil God (Satan/Ahriman). This Satan was given a bunch of extra names by the Church throughout history, such as Lucifer, Belial, and Beelzebub.
The third Satan is the one of modern demonolatry, where he is usually aligned with the name Lucifer, and is believed to be connected to every pantheon of Gods and going by different names, such as Enki, Set, among others. But any connection to Yahweh is downplayed or outright rejected.