Google Assistant is a virtual assistant developed by Google that uses natural language processing and artificial intelligence to provide voice-activated assistance.

Three key functionalities of Google Assistant:

1. Voice Commands: Users can ask Google Assistant questions, set reminders, control smart home devices, and perform various tasks using voice commands.
2. Personalization: Google Assistant learns user preferences and provides personalized responses and recommendations.
3. Integration: It integrates with various apps and services, allowing users to perform tasks seamlessly through voice interaction.