Check out example codes for "no sql". It will help you in understanding the concepts better.

Code Example 1

TLDR: NoSQL databases (aka "not only SQL") are non tabular, and store data differently than relational tables.
NoSQL databases come in a variety of types based on their data model. The main types are document, key-value,
wide-column, and graph. They provide flexible schemas and scale easily with large amounts of data and high user loads.

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