How does HTTP GET work?

HTTP GET is a method used by clients (such as web browsers) to request data from a server. When a client sends an HTTP GET request, it typically includes a URL (Uniform Resource Locator) specifying the resource it wants to retrieve. The server processes the request and responds with the requested resource, such as an HTML document, image, or other types of data. The HTTP GET method is considered “safe” and “idempotent,” meaning it should not modify server state and can be repeated without causing different outcomes.

The HTTP GET method works by appending parameters directly to the URL in the form of key-value pairs, separated by “&” symbols after a “?” character. When the server receives a GET request, it parses these parameters from the URL and processes them accordingly. For example, a GET request to fetch search results might include parameters like “?q=search+query&page=2”, where “q” denotes the search query and “page” specifies the page number of results to retrieve.

An HTTP request follows a series of steps to communicate between a client and a server:

1. URL Formation: The client constructs a URL specifying the server’s address and the resource path it wishes to access.
2. HTTP Method: The client selects an appropriate HTTP method (e.g., GET, POST, PUT, DELETE) to perform the desired action on the server.
3. Request Headers: The client may include optional headers in the request, such as “Accept” to specify the desired response format (e.g., JSON, XML) or “Authorization” for authentication purposes.
4. Body (for some methods): For methods like POST or PUT, the client may include a message body containing data to be sent to the server.
5. Sending the Request: The client establishes a TCP connection to the server and sends the HTTP request message containing the method, headers, and optional body.
6. Server Processing: Upon receiving the request, the server parses the request message, interprets the method and headers, and processes the optional message body if present.
7. Generating Response: The server formulates an HTTP response containing the requested resource, status code (indicating success, failure, or redirection), headers, and optional response body.
8. Sending the Response: The server sends the HTTP response back to the client through the established TCP connection.
9. Client Processing: The client receives the HTTP response, parses its contents, and takes appropriate action based on the response status code and body content.

HTTP works as a protocol that defines the rules for transferring hypermedia documents, such as HTML pages, over the internet. It operates on a request-response model where clients initiate requests to servers for specific resources, and servers respond with the requested data or status information. HTTP is stateless, meaning each request from a client to a server is independent, and the server does not retain information about past requests. This simplicity and flexibility make HTTP suitable for a wide range of applications, from simple web browsing to complex web services and APIs.