Huh. So I tried to look it up just now and I'm not sure if I understand the difference. (To the extent that there is one - apparently one can mean the other, but I imagine they're usually used as follows.)
It looks like "jealous" is more being afraid of losing something you have (most commonly e.g. a spouse's affection) to someone else, whereas "envious" is wanting what someone else has?
No worries. I learned this too a while ago (was also using jealous instead of envious and vice versa myself). From my understanding the use of jealous is when you have something but that is threatened by some external factor, eg a partner, a friend having more fun with somebody else. Envious is when you covet something that you do not have currently but wish to, which is in this case playing with exciting tech.