A reusable iOS component is built using Swift to provide a more efficient and maintainable way of structuring the code for an iOS application. The process involves creating a model, a table view controller, and a rating view as separate components that can be reused throughout the app. The reusable components are created by employing techniques such as composing types, nib files, and delegate patterns to make them more versatile and maintainable. These components can be easily integrated into an existing iOS application or used as a starting point for building new ones. By following this approach, developers can reduce code duplication, improve the overall structure of their app, and enhance its performance and user experience.