The document discusses MongoDB and how it compares to relational database management systems (RDBMS). It provides examples of how data can be modeled and stored differently in MongoDB compared to SQL databases. Specifically, it discusses how MongoDB allows for flexible, dynamic schemas as each document can have a different structure. This enables complex data like product catalogs with varying attributes for different items to be stored easily in a single collection. The document also provides examples of common operations like insert, update and delete in MongoDB compared to SQL.