SQLite is a lightweight, serverless, self-contained SQL database engine that stores data in a single file. It's commonly used in mobile applications because:

• Lightweight: Small footprint (~500KB library size)
• Serverless: No separate server process required
• Zero-configuration: No setup or administration needed
• Cross-platform: Works on iOS, Android, and other mobile platforms
• ACID compliant: Ensures data integrity
• Fast: Optimized for local storage and retrieval
• Embedded: Runs directly within the application process

Mobile apps benefit from SQLite's offline capabilities, allowing data persistence without network connectivity.