SQLite is a C-language library that offers a lightweight, disk-based database, which doesn't require a separate server process. It supports a self-contained, serverless, zero-configuration, and transactional SQL database engine, making it ideal for embedded database solutions. SQLite is widely used in applications due to its simplicity, adaptability, and reliability. It is public domain and offers full-featured SQL capabilities, enabling developers to operate databases efficiently without the overhead of a full database management system.