SQLite is an open-source SQL database that stores data in a text file on a device.
SQLite is a C-language library that implements a small, fast, self-contained, high-reliability, full-featured, SQL database engine. SQLite is the most used database engine in the world as it is used today by several widespread browsers, operating systems, and embedded systems (such as mobile phones).

The SQLite file format is stable, cross-platform, and backwards compatible
SQLite is free to use for any purpose commercial or private. It is a self-contained, serverless, zero-configuration and transactional SQL database engine.

SQL databases, SQLite does not have a separate server process. It reads
and writes directly to ordinary disk files. Also, it is very convenient as it’s less than 600kb in size. Lightweight in terms of setup, database, administration t and resource requirements.

Features and benefits of using SQLite
Benefits of Using SQLite
Self-contained: no external dependencies, it requires no special facilities or tools to build.
Serverless – No server or other system processes are required to run.
Configuration Not Required – No setup or administration is required.
SQLite is Transactional – SQLite implements transactions that are atomic, consistent, isolated, and durable
Totally free – Open source, therefore, no license, setup or administration is required after installation.
Storing Data is easy – Provides an efficient way to store data.
Flexible – Helps you work on multiple databases in the same session simultaneously
Single-file Cross-platform Database – It can run on all platforms
Full-Featured SQL- SQLite has a full-featured SQL implementation

Features of SQLite
Great for use as an application file format. File format can be extended in future versions simply by adding new tables and/or columns while maintaining backward compatibility.
Supports terabyte-sized databases and gigabyte-sized strings and blobs
Small code footprint: less than 600KiB fully configured or much less, it is lightweight
Simple, easy-to-use API.
Fast: In some cases, SQLite is faster than direct filesystem I/O
Written in ANSI-C. TCL bindings included. Bindings for dozens of other languages are available separately.
Well-commented source code with 100% branch test coverage.
Use for any purpose, Sources are in the public domain
Comes with a standalone command-line interface (CLI) client that can be used to administer SQLite databases.
Performance - Rather than reading the entire file and keeping a full scan in memory., it only loads data needed
Accessibility Content stored in an SQLite database can be recovered decades later

Even with all the benefits, SQLite is not the perfect application file format for every situation.
It is not suitable for large-scale apps, you will have no access to the network and the database is limited in size

SQLite’s distinctive features make it the most widely deployed SQL database engine used by most developers.