1. Human-computer interaction (HCI or HMI) is a discipline that studies the interactive relationship between a system and its users.
2. A system can be any kind of machine, or it can be a computerized system and software.
3. The human-computer interface (HCI) typically refers to the part visible to the user. Users interact with and operate the system through the HCI. This ranges from small things like a radio's play button to large things like an airplane's instrument panel or a power plant's control room. The design of the HCI must incorporate the user's understanding of the system (i.e., a mental model), which is essential for the system's usability and user-friendliness.
4. Human-Computer Interface Design: This is understood to be a specific manifestation of human-computer interaction science in engineering research and development, belonging to the discipline of human-computer interaction. To achieve better interaction and usability with users, it is essential to design the human-computer interface based on human-computer interaction science.
