SQLite is a software library that provides a relational database management system (RDBMS) implemented as a small, lightweight, and self-contained database engine. Unlike most other database systems, SQLite does not have a separate server process. It is designed to be embedded directly into applications, making it a popular choice for local data storage in a wide range of software applications and operating systems.

SQLite stores data in a single file, typically with a .sqlite or .db extension, which makes it easy to manage and transport. The entire database resides in this file, including tables, indexes, views, triggers, and other database objects. SQLite uses a transactional database engine, which ensures data integrity and provides features like atomic commits and rollback capabilities.

SQLite supports standard SQL syntax, allowing you to create tables, define relationships between tables using foreign keys, and perform various database operations like querying, inserting, updating, and deleting data. It also supports common SQL features such as joins, subqueries, views, and transactions.

One of the key advantages of SQLite is its simplicity and ease of use. It requires minimal setup and administration compared to larger database systems like MySQL or PostgreSQL. It is widely supported and available on various platforms, including Windows, macOS, Linux, and mobile operating systems like Android and iOS.

SQLite is commonly used in applications that need a local database, such as desktop and mobile applications, web browsers, embedded systems, and other software solutions that require a lightweight and reliable storage mechanism.