Arteries carry oxgenated blood away from the heart to the rest of the body. They have thick elastic walls to withstand high blood pressure being pumped from the blood. This is why they appear red in colour.
On the other hand, veins carry deoxygenated blood back to the heart. They are thin in comparison to the artery, as they are under lower blood pressure. However, veins contain valves to prevent backflow of blood as veins carry deoxygenated blood.
