The Google Assistant uses different types of information to make your experience more useful and relevant. Depending on your settings, the Assistant will reference data in your Google Account to get you what you need when you ask for help. For example, if you ask, “When is my next meeting?”, the Assistant answers your question using information from your Calendar. Or if you ask “Do I need an umbrella tomorrow?” the Assistant uses your current location to give you the most relevant answer. When you ask Google Assistant for something that requires personal information on a shared device, such as a smart display or smart speaker, the Assistant attempts to recognize you using technologies such as Voice Match or Face Match to protect your privacy. If you have not enabled those features or turned on Personal Results on the device you are using, the Assistant will not give you personalized results on that device. Even if Assistant recognizes you, some information, such as your work calendar appointments, may not be available based on the privacy configuration set by your company's system administrator.
You can also use the My Activity web site to view, manage, and delete your activity with Google services, and to manage the activity controls in your Google Account that let you decide what data is saved and used across Google services. For some types of activities and content, such as news and recipes, you can set specific preferences in the settings page for Google Assistant.
Google Assistant always uses other criteria, such as overall popularity and average user ratings for content, and not just your own activity to determine the best responses to your requests. When you access other services through Assistant, such as music or video streaming, those services may apply their own ranking systems and personalization criteria to respond to your requests.
Depending on what you ask Google Assistant, it may also ask you to use the context of your device or your environment to better help you. For example, if you ask Assistant to navigate to the nearest grocery store, it may use the geographic position of the device you are using to find a nearby store and then provide you with directions. Similarly, if you ask Assistant, "Are the kitchen lights on?", it may use information from devices you linked to Google Home to check and let you know.