The HTTP request lifecycle is a series of steps that occur when a client sends an HTTP request to a server and the server responds with an HTTP response. Below is a detailed explanation of each step in the lifecycle.
Steps in the HTTP Request Lifecycle
Client sends an HTTP request: The lifecycle begins when a client (such as a web browser) sends an HTTP request to the server. This request can be a GET, POST, PUT, DELETE, or any other HTTP method.
- GET: Requests data from a specified resource.
- POST: Submits data to be processed to a specified resource.
- PUT: Updates a specified resource.
- DELETE: Deletes a specified resource.
Server receives the HTTP request: The server receives the HTTP request and processes it. The server checks if the requested resource exists and if the client has the necessary permissions to access it.
Server processes the HTTP request: The server processes the request by performing the necessary actions. This could involve retrieving data from a database, performing calculations, or any other server-side operations.
Server sends an HTTP response: Once the server has processed the request, it sends an HTTP response back to the client. This response includes a status code (such as 200 for success or 404 for not found), headers, and the requested data.
Client receives the HTTP response: The client receives the HTTP response and processes it. If the response is successful, the client may display the requested data or perform further actions. If the response indicates an error, the client may display an error message to the user.
Example
Let's say you want to retrieve the content of a webpage using a GET request:
- You type the URL into your web browser.
- The browser sends a GET request to the server.
- The server processes the request and sends back the webpage content.
- The browser receives the webpage content and displays it to you.
For more information on HTTP requests, you can visit our HTTP Basics guide.