SQL vs NoSQL
SQL stores data in tables with a fixed structure. NoSQL stores it in other shapes, like documents or graphs.
When you pick a database, the first fork in the road is usually this one: SQL, or NoSQL.
What they are
SQL databases store data in tables with a fixed structure, linked by relationships. NoSQL is a family of databases that store data in other shapes: documents, key and value pairs, wide columns, or graphs.
How they work
In Postgres or MySQL, you define the columns up front, the database enforces them, and you can join tables together in one query. In a document store like MongoDB, each record is a flexible, JSON-like document, and related data often lives together in one place.
Why it matters
SQL shines when data is connected and correctness matters, like money. NoSQL shines when the shape changes a lot, or you need to spread huge volumes across many machines.
