Need a simple explaination for this. what is varicose veins?

Define Varicose Vein: This is an abnormal enlarged bulging vein beneath the skin that is under elevated pressure as the result of faulty valves within that section of vein. Often there is also another underlying deeper faulty vein that is causing the surface vein to devlop & bulge, so ultrasound is recommended to evaluate for a potential underlying source. The blood inside a varicose vein is often traveling backwards.

Normal veins carry: old blood from the leg. The heart does not have enough power to pump all the old blood out, so veins have little flaps inside that act as check valves, forcing the blood to move up and out. Varicose veins have broken valves, so gravity can pull old blood backward. This causes pressure that dilates and twists the veins. Also, tissues bathed in the old blood can become irritated and damaged.

Varicose veins: varicose veins are enlarged areas of vein which are located just under skin. It is thought that the wall of the vein becomes weak in some sections. These sections then widen and become more prominent . If this occurs near a valve then the valve may become leaky and blood may flow backwards which causes extra pressure on the vein. This can cause more widening and vein stands out.