How APIs Work

APIs function as intermediaries that process requests and ensure the correct data or functionality is delivered. Here's a step-by-step explanation of how APIs typically work:

1. The Request

When an application wants to access data or functionality from another system, it sends a request to the API. The request includes:

• An Endpoint: This is the URL where the API is hosted. It specifies the resource you are trying to access.

• Method: The type of action you want to perform, such as:

  • GET: Retrieve information from the server.

  • POST: Send new information to the server.

  • PUT: Update existing information on the server.

  • DELETE: Remove information from the server.

• Headers: Additional information like authentication details, content type, etc.

• Data (or Body): The actual information being sent, usually in JSON or XML format, especially for methods like POST or PUT.

2. The Processing

Once the request is received, the API processes it based on the rules and permissions set by the API provider. This may involve querying a database, performing a calculation, or retrieving some data from another service.

3. The Response

The API then sends a response back to the requesting application. The response usually includes:

• Status Code: Indicates whether the request was successful (e.g., 200 OK) or if there was an error (e.g., 404 Not Found, 500 Internal Server Error).

• Headers: Additional metadata about the response.

• Data: The requested information, often in a structured format like JSON or XML.