MongoDB is a NOSQL database, cross-platform, document oriented database that provides, high performance, high availability, and easy scalability. MongoDB works on concept of collection and document. Any relational database has a typical schema design that shows number of tables and the relationship between these tables. While in MongoDB, there is no concept of relationship. Advantages of MongoDB over RDBMS
Schema less − MongoDB is a document database in which one collection holds different documents.
No complex joins.
Deep query-ability. MongoDB supports dynamic queries using a document-based query language that's nearly as powerful as SQL.
Ease of scale-out − MongoDB is easy to scale.
Conversion/mapping of application objects to database objects not needed.
Uses internal memory for storing the (windowed) working set, enabling faster access of data.
Why Use MongoDB?
Document Oriented Storage − Data is stored in the form of JSON style documents.
Index on any attribute
Replication and high availability
Fast in-place updates
Professional support by MongoDB