The paper presents the impact that emotions have on human life, the complex nature of emotions and the components of emotions as the necessary conditions for their formation, which sought to explain what emotions are using an example of an emotional state of anger. Also, because of the similarity of emotions and mood, part of the work is dedicated to distinguishing them. After explaining the emotions and their importance, the attention of the work is directed towards emotion theories that present different ideas about what emotion is and how it is created, and the disadvantages of theories are presented. The paper also focuses on discussions about the existence of basic emotions and how understanding the origin of emotions affects the way they exist. Two theories on the origin of emotions, evolutionary theory of emotions and social constructivism are listed. Social constructivism is illustrated using the example of emotional differences between people in the east and west, while the evolutionary theory of emotion is supported by pointing to similarities between emotional expressions between animals and humans and by examples of evidence of evolutionary development of emotional expressions in humans.