Firestore
Introduction
Cloud Firestore is a flexible scalable NoSQL database for storing and managing data for mobile, web, and server development. It helps keep client apps sync through realtime listeners and offline support. Firestore works seamlessly with other Firebox and Google Cloud Platform products.
Data Model
Firestore is a NoSQL, document-oriented database that stores data in documents, which are organized into collections. Each document is made up of key-value pairs and must be stored in a collection. Documents may also contain subcollections and nested objects.