Google Home speakers enable users to speak voice commands to interact with services through Google's intelligent personal assistant, called Google Assistant.
Alexa is an intelligent personal assistant developed by Amazon
HomeKit is Apple's home automation platform for controlling smart home products with iOS apps and Siri voice commands.
Nest Labs is a home automation producer of programmable, self-learning, sensor-driven, Wi-Fi-enabled thermostats, smoke detectors, security cameras, and other security systems.
Ring is a home automation company that makes the Ring Video Doorbell, a smart doorbell.