This document introduces MongoDB, an open-source document-oriented database. It discusses how MongoDB stores data as JSON-like documents rather than in tables, supports dynamic schemas, and is horizontally scalable. Some common use cases for MongoDB are also listed, including single view applications, IoT, mobile, real-time analytics, personalization, catalogs, and content management. The document concludes by covering how Habilelabs uses MongoDB with Node.js for REST API projects.