Let us here dispel a foolish notion that exists in the minds of some people about this commandment: This holy commandment does not imply that there are other gods besides God and that God is selfish and want humans to worship Him only and is here discouraging humans from worshiping any of the other gods.
No! No! What is meant here is that God does indeed exist -- He is the one and only true God and there is no other. From that vantage point, He commands humans not to foolishly endeavor to create gods, for whatever they fashion mentally or corporeally will not be the true God. And He commands them not to regard any human, angel, demon, animal or thing to be a god, for whomever or whatever they regard to be gods will not be the true God. In other words God requires that humans understand that God exists alone, and nothing else exists other than what He has created, and to regard anyone or anything to be gods would be regarding the things He has created to be gods. By so doing, one ends up worshiping the creature rather than the creator (Romans 1:18-28).
Therefore God requires that He should be understood and acknowledged as the true God, and understood and acknowledged that no one and nothing else can rightly hold His position or title. He requires that the honor, obedience and worship which humans are responsible to give to Him should never be given to anyone or anything other than to Him.