SQLite is a software library that implements a self contained, serverless, zero configuration, transactional SQL database engine. SQLite is one of the fastest growing database engines around, but that's growth in terms of popularity, not anything to do with its size. The source code for SQLite is in the public domain. SQLite is a database itself like we have MySql Server.
SQLite engine is not a standalone process like other databases, you can link it statically or dynamically as per your requirement with your application. The SQLite accesses its storage files directly.