What exactly is the relationship between pressure drop in blood vessels and resistance

I know the equation Pressure = Flow X Resistance
The textbook says that the biggest pressure drop occurs at the arterioles because they have the most resistance. How does increasing resistance cause a pressure "drop"? According to the equation aren't pressure and resistance directly related?

There are lots and lots of arterioles, so even though the resistance in ONE arteriole is higher, there are so many of them that the pressure drops because the overall resistance to flow decreases.

Remember, arteries branch. The cross sectional area of the sum of the branched arterioles is larger than the cross sectional area of the artery before it branched.

If the resistance in the artierioles increases, the blood flow through the following parts is reduced. When there's no blood flow, there's no pressure...