I cannot understand the difference between omega 3 and 6. i take both 3 and 6 in equal amount supplements and it makes my skin brilliant. ?

Both essential yet..: Both omega 3 & 6 fatty acids are essential for health. One does not substitute for the other but many foods contain both. Deficiencies can cause not only dry skin but depression, joint pains, menstrual cramps, poor immune function etc. Deficiency of Omega 3's is more common. See http://www.nutritionmd.org/nutrition_tips/nutrition_tips_understand_foods/fattyacids.html for more details.