API Design: This involves designing the structure, functionality, and endpoints of the API. It also involves defining the data formats and protocols that will be used to exchange information between the API and other applications.

API Development: This involves writing the code for the API, using programming languages such as Python, Java, or JavaScript. The code will be responsible for handling requests from other applications, performing data processing, and sending responses back to the requesting application.

API Documentation: This involves creating documentation that describes the functionality and usage of the API. The documentation should include information such as endpoint URLs, request and response formats, and error handling procedures.

Testing: API developers are responsible for testing the API to ensure that it is functioning as intended. This includes testing different use cases, handling errors and exceptions, and ensuring that the API can handle high volumes of requests.

Deployment: Once the API is developed and tested, API developers are responsible for deploying it to a production environment. This involves configuring servers, setting up security measures, and ensuring that the API is accessible to authorized users.