Human-computer interaction (HCI) is defined as the study of how humans interact with computers and to improve that interaction. HCI aims to improve usability, safety, effectiveness and efficiency. Specifically, HCI seeks to make computers more usable by focusing on learnability, memorability, safety and the ability of the system to do what it is intended to do. HCI draws from multiple disciplines including psychology, cognitive science, ergonomics, computer science and graphic design.