Cholesterol is a four-ring aromatic compound with a tail, derived from a precursor molecule called a stanol.

“so the precursor molecule is called the stirring so you have the the rings the four rings and you may or may not have this tail sticking off of the 17 carbon in the fourth ring so all of the bonds are saturated that is called the stirring so if you unsaturated one double bond in that strain it's called the stirring and if you then stick a hydroxy group on the third carbon in the first ring it's called the star or it's an alcohol because you got a hydroxy group now sticking out hydroxy being Oh H oxygen excuse me correct”