The Atlassian Jira Issue Link Type API is a tool that allows users to create and manage different types of links between issues in Jira. This API enables developers to establish relationships between issues, such as dependencies, related issues, or sub-tasks, providing a way to organize and track the progress of a project more effectively. With this API, users can customize and define their own link types to suit their specific needs, making it easier to navigate and understand the relationships between different issues within Jira. Overall, the Atlassian Jira Issue Link Type API enhances collaboration and communication among team members, helping to streamline workflows and improve project management processes.