The Atlassian Jira Issue Type Screen Scheme API is a tool that allows users to customize the screens that are displayed for different issue types in their Jira project. With this API, users can create and manage screen schemes that define which screens are associated with each issue type in their project. This allows users to tailor the user interface to best suit the needs of their team and project, ensuring that the necessary information is easily accessible and properly organized. The API provides a flexible and customizable way to optimize the user experience within Jira and improve workflow efficiency.