Idolatry worships the created rather than the Creator. It's in the Bible, Romans 1:22-23, TLB. "Claiming themselves to be wise without God, they became utter fools instead. And then, instead of worshipping the glorious, ever-living God, they took wood and stone and made idols for themselves, carving them to look like mere birds and animals and snakes and puny men."
The commandments forbid the worship of idols and images. It's in the Bible, Exodus 20:3-4, NIV. "You shall have no other gods before Me. You shall not make for yourself an idol in the form of anything in heaven above or on the earth beneath or in the waters below. You shall not bow down to them or worship them; for I, the Lord your God, am a jealous God, punishing the children for the sin of the fathers to the third and fourth generation of those who hate Me, but showing love to thousands who love Me and keep My commandments."