It is important to distinguish between jealousy and envy as they are both very different, and knowing the differences will make us aware if we are simply envious (easy to fix) or jealous.
Imagine you saw your wife with her ex-boyfriend...
would you be jealous or envious? Imagine a friend that has inherited a large amount of money, would you feel jealous or envious? To most people, they would describe both scenarios as jealousy, when in fact only the first is jealousy.
Envy involves only two people.
You want something (object can be anything from their mate, their attractiveness, success or popularity) that someone else has...
and you don't want them to have it.
It can be a healthy emotion because it can spur you to achieve goals you might otherwise not achieve.
But generally, envy is more an expression of hostility to something that you perceive as better.
Jealousy involves three people, and makes you lose your goals..
there is a threat posed by a third person to a valued relationship that you have (a romantic relationship involving two people), and this third person can be either real or imagined (the love which you are receiving as man from your woman is in danger of being taken away)...
Most of the time with jealous men, it is only imagined.
This may cause the man to be smothering, angry and controlling to try to protect what is his.
Jealousy does have a component of envy in there as well.
For example if a man stole your woman from you, you will obviously have feelings of jealousy there, but you will also be envious of what he has.
But in general, the two descriptions above serve you well to explain the differences between the two.
Take a man dancing with your girlfriend for example...
a jealous man would think that she should only want to dance with him.
An envious man would think I wish I could dance as well as he does...