Android has had a robust voice command system in place for ages. The number of things Android can do for you is expanding all the time. For a fully hands-free experience, you’ll need to set up always-listening voice control. Android is smart enough to recognize word variations; so, for example, itll respond whether you say Turn Wi-Fi on, Pump up the volume or Enable/disable battery saver mode”]
Source: https://www.computerworld.com/article/3094831/ok-google-160-valuable-voice-commands-for-android.html