Jealousy and envy are often used interchangeably, but they have distinct meanings.
Jealousy is the fear of losing something important to you, such as a relationship or a possession, to someone else. It involves feelings of insecurity, possessiveness, and a desire to protect what you have.
Envy, on the other hand, is the desire to have something that someone else has, such as a particular skill, trait, or possession. It involves feelings of discontentment, resentment, and a longing for what you lack.
In short, jealousy is the fear of losing what you have, while envy is the desire for what you don't have.