HCI stands for Human-Computer Interaction, which is the field that deals with the design and development of computer technology and its interaction with humans. It involves analyzing, designing, and evaluating the user interface of computer systems to make them more user-friendly, efficient, and effective. There are various synonyms for HCI, including interface design, user interaction, ergonomics, usability engineering, user-centered design, and interactive system design. These synonyms all refer to the same field of study and deal with making computer technology more intuitive and human-friendly. The goal of HCI is to create computer systems that are accessible, usable, and enjoyable for people to use.