Ask ten different people and you might get ten different views on how the emotions of envy and jealousy are distinct.
I turns out that Psychologists agree on a fairly straightforward distinction.
Envy occurs when we lack a desired attribute enjoyed by another.
Jealousy occurs when something we already possess (usually a special relationship) is threatened by a third person
And so envy is a two-person situation whereas jealousy is a three-person situation. Envy is a reaction to lacking something. Jealousy is a reaction to the threat of losing something (usually someone).
This seems straightforward, and so why the confusion?