The differences between MongoDB and RDBMS are many in various aspects. MongoDB is a NoSQL database that is document-oriented. It stores data in the form of a Binary JavaScript Object Notation, which is further stored in a collection. RDMS, on the other hand, is a relational database management system. MongoDB is scalable, horizontally and vertically, but RDBMS is only vertically scalable. MongoDB isn’t equipped enough to work with difficult joins whereas RDBMS is supportive of complex joins. Another big difference is with the processors. As the number of processors increases in MongoDB, the performance enhances. However, in RDBMS, the performance is based entirely on the RAM capacity.