Mockaroo is an online tool that allows users to generate realistic sample data for testing and development purposes. It provides a user-friendly interface where users can customize the type of data they need, such as names, addresses, dates, and more. This helps developers and data analysts create datasets that mimic real-world scenarios without compromising sensitive information. The platform supports various output formats, including CSV, JSON, and SQL, making it easy to integrate the generated data into different applications. Users can also save their data generation configurations for future use, streamlining the process of creating test datasets.