Voice user interface (VUI) is a speech recognition technology that allows people to interact with a computer, smartphone or other device through voice commands. VUI uses voice as the primary mode of interaction, in contrast with the traditional keyboard-mouse-monitor combination or touch screen. This voice-first approach can allow users to initiate automated services and execute their day-to-day tasks in a faster, more intuitive manner. Apple’s Siri, Amazon’s Alexa, Google’s Assistant and Microsoft’s Co-Pilot are prime examples of VUIs.