SQLite is a free and open source relational database management system. It is embedded into the end program.
From the blog post:
SQLite is a self-contained, serverless SQL database. Dr. Richard Hipp, the creator of SQLite, first released the software on the 17th of August, 2000. Since then it has gone on to be the second most deployed piece of software in the world. It’s used in systems as important as the Airbus A350 so it comes as no surprise the tests for SQLite 3 are aviation-grade. The software itself is very small, the amd64 Debian client and library package is 765 KB when compressed for distribution and 2.3 MB when fully installed. The software is licensed under a very promiscuous license: Public Domain.
- Read more: A Minimalist Guide to SQLite