Emotional intelligence was introduced in 1990 and refers to the human capacity to understand and manage emotions in oneself and others. It involves directing emotions in a balanced way rather than stifling them. There are three main models of emotional intelligence: Salovey and Mayer's ability model, Bar-On's mixed model, and Goleman's competency model. These models involve skills like emotional perception, facilitation of thought with emotion, understanding of emotion, and reflective regulation of emotion to promote personal growth. Emotional intelligence is seen as complementary to cognitive intelligence and important for work performance and relationships.