HCI - human-computer Interaction
Short for human-computer Interaction, a discipline concerned with the study, design, construction and implementation of human-centric interactive computer systems. A user interface, such as a GUI, is how a human interacts with a computer, and HCI goes beyond designing screens and menus that are easier to use and studies the reasoning behind building specific functionality into computers and the long-term effects that systems will have on humans.
HCI is a very broad discipline that encompasses different specialties with different concerns regarding computer development: computer science is concerned with the application design and engineering of the human interfaces; sociology and anthropology are concerned with the interactions between technology, work and organization and the way that human systems and technical systems mutually adapt to each other; ergonomics is concerned with the safety of computer systems and the safe limits of human cognition and sensation; psychology is concerned with the cognitive processes of humans and the behavior of users; linguistics is concerned with the development of human and machine languages and the relationship between the two.
As computers become more and pervasive in culture, designers are increasingly looking for ways to make interfacing with devices easier, safer and more efficient.