Emotional Intelligence (EI) is the ability of a person to identify, manage and control own emotions and the emotions of others. Emotional intelligence is also known as the capability of a person to recognize own emotions and those of others and label them appropriately, and use emotional information to manage or control the thinking and behavior of self and of others.

So, what it means is, a person with emotional intelligence (or an emotionally intelligent person) can recognize and control her/his/their own emotions, and also, can recognize and control the emotions of other people.

Emotional intelligence (EI) is variedly expressed as Emotional Quotient (EQ), Emotional Intelligence Quotient (EIQ) and Emotional Leadership (EL).

Emotional intelligence is often said to have these five key elements:

1. self-awareness
2. self-regulation
3. motivation
4. empathy, and
5. social skills

Studies have shown that people who possess emotional intelligence have at least three skills:

1. emotional awareness: the ability to identify and name their own emotions,
2. harnessing emotions: the ability to utilize those emotions and apply them to tasks like thinking and problem solving, and
3. managing emotions: the ability to manage emotions that includes regulating own emotions when necessary and also helping other people to do the same

In short, an emotionally intelligent person is highly conscious of her/his/their own emotional states like joy, pain, frustration, sadness etc. while identifying them accurately and managing them and can do the same with other people.

Researchers have found that people with high EI have better mental health, greater job performance, and higher leadership skills, although many other researchers do not fully agree with that view as the latter ones believe that better performances are rather associated with general intelligence.

Emotional intelligence, as a psychological theory, was developed in the late 1980s by Peter Salovay and John Mayer. The concept became an issue of global awareness soon after the publication of the book 'Emotional Intelligence' in 1995 by science journalist and author Daniel Goleman.