MongoDB is a NoSQL database management system that uses a document model to store data in structured JSON (JavaScript Object Notation) documents. This database has drivers for a number of programming languages, such as Java, Python, and Ruby. MongoDB has features that help scale and performance, such as the ability to store complex and large amounts of data, distributed programming and replication, fast indexing, and shard support. This database is commonly used for web and mobile applications, as well as big data analytics and the Internet of Things (IoT).