The purpose of the research is just to discuss the benefits and capabilities of facial expression recognition. Facial expression is a type of non-verbal communications that plays an important part in both verbal and non-verbal communications. It expresses a person's point of view or attitude, as well as his or her mental state. Over the last 20 years, a significant amount of experimentation had already been conducted for optimize Human Computer Interaction (HCI). This article covers the following topics: an introduction to facial emotion recognition systems, their applications, a comparison of popular face expression identification approaches, and the stages of an automatic facial expression identification system. Emotions factors have a significant influence on social intelligence, such as interaction understandings, making decisions, and comprehending human behaviour at the time of conversation, emotion is really important. Emotions recognition could be done in a variety of ways, including verbal and nonverbal methods. Voices (Audio) are a type of spoken conversation. Nonverbal conversation includes facial expressions, actions, bodily orientations, and gestures.  When speaking, the spoken component overall provides just 7% of the statement's impact, the audible component provides 38%, and also the subject's facial expression provides 55% of the message's consequences. As a result, automatic and significant facial expressions will be advantageous in human-machine interaction. From human services to healthcare operations, facial expressions interpretation might be beneficial. Facial expressions interpretation is beneficial for technologies including HCI, Friendly Robots, Animations, Surveillance Systems, and Pain Detecting in Healthcare that are mainly focused around emotional identification.
Key words: Facial expressions, Emotion recognition, Human Computer Interface, gestures.