MongoDB is a NoSQL, document-oriented database that stores data in flexible, JSON-like documents called BSON. Unlike relational databases, MongoDB does not require a predefined schema, allowing for dynamic and diverse data structures. This flexibility makes MongoDB ideal for applications with large, unstructured, or evolving datasets such as social media platforms or content management systems. Its ability to scale horizontally across multiple servers enables it to handle high volumes of data efficiently.

MongoDB supports powerful querying, indexing, and aggregation features, enabling developers to perform complex data operations with ease. It works seamlessly with technologies like Node.js and Express, making it a popular choice in full-stack JavaScript development. MongoDB's scalability, flexibility, and rich query language allow developers to create fast and robust applications that can handle large, dynamic datasets.