An HMI or human-machine interface enables interaction between the operator (user) and the electrical device or machine. This interaction can take on different forms: From a pure display function, e.g. a classic monitor frame, to a multimodal HMI system that combines haptic, visual and acoustic input and feedback options with computing power and other features.
Conceptually, an input system is a part or the complete HMI, depending on how the evaluation, communication and computing power within the machine is designed. In this context, HMIs can be designed from embedded systems to full-fledged (I) PCs. The difference is that in the embedded case, the function of the system is limited or optimized to the execution of the specific device tasks, while the PC version offers a much broader range of services.