Spider veins are fine, pink, thread like veins. They are often seen in association with larger blue or ‘reticular’ veins.
Reticular veins are usually several mms in diameter and may bulge very slightly on standing. Varicose veins tend to bulge out from the skin, more so when standing. These are more likely if there is a family history of varicose veins or there has been previous vein surgery.
The photographs on this website may help you with identification.