HTTP (Hypertext Transfer Protocol) is the foundation of data communication on the web. It defines how messages are formatted and transmitted, and what actions web servers and browsers should take in response to these messages.

Key Components of HTTP

  • Client-Server Model: HTTP operates on a client-server model, where the client (usually a web browser) requests data from a server.
  • Request-Response Cycle: When a client makes a request, the server processes it and sends back a response.
  • HTTP Methods: These are actions that can be performed on a resource. Common methods include GET (to retrieve data), POST (to submit data), PUT (to update data), DELETE (to delete data), etc.

Request and Response Structure

Request

A typical HTTP request has the following structure:

  • Method: The HTTP method being used (GET, POST, etc.).
  • URI: The Uniform Resource Identifier (URL) that specifies the resource being requested.
  • Headers: Additional information about the request, such as the type of data being sent, the client's IP address, etc.

Response

A typical HTTP response has the following structure:

  • Status Code: A three-digit number indicating the result of the request (e.g., 200 OK, 404 Not Found).
  • Headers: Additional information about the response, such as the content type and length.
  • Body: The actual data sent back to the client.

Common HTTP Status Codes

  • 2xx: Success (e.g., 200 OK, 201 Created)
  • 3xx: Redirection (e.g., 301 Moved Permanently, 302 Found)
  • 4xx: Client Error (e.g., 404 Not Found, 403 Forbidden)
  • 5xx: Server Error (e.g., 500 Internal Server Error, 503 Service Unavailable)

Additional Resources

For more information on HTTP, you can visit the following resources:

HTTP Diagram