The main difference between envy and jealousy is that envy is an emotion related to coveting what someone else has, while jealousy is the emotion related to fear that something you have will be taken away by someone else.
edit Video explaining the differences
Envy is a desire to possess what someone else has. For example,
- She was envious of her friend who vacationed in exotic places and posted her pictures on Facebook.
Jealousy is the fear that what you possess will be taken from you. For example,
- Jane's harmless flirting with the valet was enough to throw her boyfriend into a fit of jealous rage.
"Envy vs Jealousy." Diffen.com. Diffen LLC, n.d. Web. 2 Sep 2014. < http://www.diffen.com/difference/Envy_vs_Jealousy >