Lesson 1 / 22

What is MongoDB?

A NoSQL document database, and how it differs from relational databases.

NoSQL & document databases

MongoDB is a NoSQL document database — it stores data as flexible, JSON-like documents instead of rows in fixed tables.

vs relational databases

Relational DBs use fixed-column tables and joins across many tables. MongoDB uses collections of self-contained documents — related data is often nested right inside one document.

Spreadsheet vs folder

A relational table is like a strict spreadsheet — every row must have the same columns. A MongoDB collection is like a drawer of folders — each folder (document) can hold slightly different papers.

When to reach for MongoDB

Great fit for evolving schemas, deeply nested data (profiles, catalogs, logs), and apps that need to iterate fast without migrations.