The document provides an overview of human-computer interaction (HCI), including key definitions and concepts. It discusses how HCI draws from multiple disciplines including computer science, psychology, and ergonomics. The document also describes several HCI design models, including the waterfall model and star life cycle model. It examines different types of interfaces such as graphical user interfaces, virtual reality, and natural language interfaces. Eye tracking research methodology is also briefly discussed as a way to study what users look at when interacting with computers.