It isn't hard to figure out, though it's the longest commandment for being shortened to "no graven images" it really says:
20:4 Thou shalt not make unto thee any graven image, or any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth.
20:5 Thou shalt not bow down thyself to them, nor serve them: for I the LORD thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me;
20:6 And shewing mercy unto thousands of them that love me, and keep my commandments.
How hard is that? Don't make any images of any animals, birds, fish etc or bow down to them or God is going to punish, you, your children, your grandchildren, your great grandchildren, and your great great grandchildren. This is clearly the basis for our modern laws, for example, my great great grandfather Ole Peter Christiansen drew a picture of a goat... which is why I'm writing this in prison.