It is a person’s ability to be able to identify and manage one’s and other’s emotions and feelings. Such people display three main characteristics,

Observing and being able to identify different emotions, can be other’s as well their own

Being able to use those emotions effectively in everyday routine

Also being able to control and manage these emotions (either your own or other’s) efficiently.

The people with such abilities are able to lead a successful and healthy life while others who are not able to master emotional intelligence, are then unable to handle situations and problems and thus succumb to depression which can later lead to other fatal issues.