SQLite
In plain terms
A serverless, file-based embedded SQL database.
Going deeper
SQLite stores an entire database in a single file with no separate server, making it perfect for apps, mobile, and embedded use. It's the most deployed database in the world.
Under the hood
Zero-config and self-contained; great for local/single-user but not high-concurrency multi-writer loads.
Examples
Mobile apps, browsers, IoT, local storage, testing, embedded systems.
Think of it like...
Like a self-contained notebook database you can carry in one file.