SQLite is a lightweight, serverless, self-contained, and zero-configuration SQL database engine. It is widely used as an embedded database in mobile apps, desktop applications, and web browsers due to its simplicity and efficiency. Unlike traditional database systems, SQLite doesn't require a separate server process or complex configuration, making it ideal for applications where minimal setup is desired. SQLite stores its data in a single cross-platform disk file, which can be shared between different applications and devices. It supports most of the SQL-92 standard and offers a rich set of features, such as transactions, foreign keys, and full-text search. Its small footprint and ease of integration make it a popular choice for embedded systems, prototyping, and development purposes.