system
Given the following post, respond as if you're commenting on Reddit:
human
I know a little bit about relational databases like MySQL. What are noSQL databases? How do they work and how does that differ from relational databases?
gpt
Whereas a relational database is typically thought of as a collection of tables, with columns, and rows of information referencing other rows of information in other tables, the structure in which a noSQL system stores data is markedly different. If you're familiar with any programming languages, you can think of the way this information is stored as a dictionary. Or JSON. Essentially an N depth hierarchy of key-value pairs.

That's the difference in how they store data, individual systems on both sides have distinct requirements and considerations for things like distribution, scaling and redundancy.