Interesting! My first reaction is that they are simply synonyms. Upon checking, they do seem to be used in slightly different circumstances. Envy is the desire to possess. There might be a desire to be like someone, or to have what they have. I agree with Soha - it's more formal, so you're more likely to see this in writing than hear it. Jealousy involves resentment, fear, or suspicion. There might be a rival with whom one is competing. You want what You Think That They have AND you don't want them to have it. Neither one is positive. etymonline.com gives an interesting comparison of their origins, which can help you get a feel for the word. I'm really enjoying the thought-provoking questions and ideas in this community. Thank you for asking this question!

Jealous means feeling unhappy because somebody has sth that you want and cannot have,for example Sarah had always been jealous of her sister's long blond hair. Envious is used specially in written and means wishing that you had sth nice or special that sb else has. When I saw the garden, I was really envious.

these two tave nearly same meaning,but the difference is-we feel envious for something we dont have..and feel jealous for something we have,but at the same time having a feeling of insecurity

I think envious is the reaction of lacking something whereas jealous is more to feel threatened of losing someone