HMI products -
read more on their website, nowadays come in numerous kinds and sizes, and may refer to either software or hardware. The hardware is generally determined by the software side of the HMI. The program is where you develop your displays, choose the data to be shown, and design the user experience you want to provide. The screen's hardware may be a standard computer, a current ThinClient / Server system, a separate HMI screen built by a controls vendor, or even the buttons and lights from yesterday.