Named Maps API allows users to create dynamic visualizations from private data, enabling filtering and modification capabilities while maintaining security. The API provides a way to define parameters that can be used in SQL and CartoCSS to change visualizations on the fly, allowing for interactive maps with secure data. This feature enables users to pass parameters to filter data or redefine designs based on user interactions without exposing sensitive information. The Named Maps API is designed to provide an easy-to-use solution for creating dynamic maps from secure data, making it easier for users to create interactive and secure visualizations.