SQLite is an embedded SQL database that implements common SQL features. It stores each database in a single file and is open source, free, and used by many applications including Firefox, Safari, and Apple Mail. Some advantages are that it is self-contained, easy to set up, and has no server requirements. It supports ACID transactions and has a small memory footprint. SQLite is generally suitable for simple applications that need local data storage, while larger projects requiring enterprise features may need a different database system.