Human-Computer Interactions (HCI) focus on devices and programs allowing users to interact with computer-based systems in an efficient and pleasant fashion. They can also be used to involve these users in the elaboration of such systems.
There are many different possible means of interaction, which are not necessarily exclusive within the same system. Indeed, a given system can for instance combine touch devices, graphical interfaces and vocal interfaces.
The consistency, ergonomics, usability and accessibility of these interaction means are therefore critical to improve the user experience and quality of computer-based systems.
HCI are sometimes referred to as Man–Machine interaction (MMI) or Computer–Human Interaction (CHI).