Postman is a popular tool used by developers to test and manage APIs (Application Programming Interfaces). It provides a user-friendly interface that allows users to send requests to a server and receive responses, making it easier to understand how different parts of a web application communicate with each other. With features like collections and environments, developers can organize their API requests and streamline their workflow. In addition to testing, Postman also offers collaboration features, enabling teams to share their API documentation and requests. This helps ensure that everyone is on the same page and can work together efficiently, ultimately leading to better software development and faster project completion.