A spider vein is a very tiny superficial vein, that is strictly cosmetic in nature. They are treated by injecting a sclerosant into the vein.
A Reticular Vein is a larger vein, usually blue/green in color.
A Varicose Vein is a large vein usually coming from a medical issue called
venous insufficiency. Varicose Veins are generally treated with Endovenous Laser Therapy (EVL).