# What is MongoDB? — MongoDB Fundamentals: Documents, Queries and Indexes

Source: https://www.skillbyai.com/en/mongodb/mongo-intro

> Learn what MongoDB is, how its JSON-like document model differs from relational tables and when it is a good fit.

## 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.