In any RDBMS system the data has a structure of tables, fields and records. The rows of the table represent the data you are storing. Each RDBMS system has different ways of managing how the tables and the relations between them are stored and manipulated. Apart from the tables you are working with other database objects, all design to correlate and provide speed for accessing the information: Indexes, Constraints, Triggers, Sequences, Synonyms, Views. The Oracle database management system is by far the most complex one.
A non-relational database management system, or NoSQL is just the opposite. In a database system like MongoDB, the data is only structured in Collections but apart that there are very few constraints. Because of this NoSQL db systems can scale horizontally very well, and due to the ever-increasing amounts of data that our applications have to work with, the ability to scale horizontally is a key factor. On non-relational databases the data is stored in files ( simple structures ) which makes it easier for the information to be replicated between a connection of servers, thus the scalability. strong text
