Google Maps uses information about previously done searches and localization information, in order to provide personalized information about places. While using Google Maps, you can find information, about the places, provided by other uses such as pictures or reviews. This way you can know better the place beforehand. There is also information provided by partners, who have actually payed, to add that information.
Google Duo is a no-frills video calling app for Android and Apple devices. It is an alternative to Apple's Facetime and makes video calling easier between Android and iOS ecosystems. Google launched Duo just for Smartphones and tablets initially but it now works on computers as well.