The .sqlite3 file extension is commonly used for SQLite database files. SQLite is a self-contained, serverless, zero-configuration, transactional SQL database engine. It is embedded directly into the end program, unlike client-server database management systems (DBMS) such as MySQL or PostgreSQL. This means that the database is stored in a single file on disk, making it highly portable and easy to distribute. SQLite databases are widely used in applications, embedded systems, and websites for storing and managing structured data. They are particularly well-suited for applications that require local data storage without the overhead of a full-fledged DBMS. The .sqlite3 file contains the entire database schema, tables, indexes, and data. Because of its simplicity and ease of use, SQLite is a popular choice for mobile applications, desktop software, and even some web applications where scalability is not a primary concern. The file format is well-documented and supported by a wide range of programming languages and tools.