The HTTP (Hypertext Transfer Protocol) request message is sent by the client to the server to request a resource or perform an action. The HTTP request message consists of several parts, including:
Request line
This is the first line of the HTTP request message, and it specifies the method, URL, and HTTP version of the request. For example:
GET /index.html HTTP/1.1
In this example, the method is “GET”, the URL is “/index.html”, and the HTTP version is “HTTP/1.1”.
Request headers
Request headers provide additional information about the request, such as the type of client making the request, the type of data being sent or accepted, and the preferred language or character encoding. Some common request headers include:
Host: www.example.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Request body
The request body contains any data that the client wants to send to the server, such as form data or a JSON payload. Not all HTTP requests have a request body.
The complete HTTP request message consists of the request line, request headers, and request body (if present) separated by a blank line. The structure of the HTTP request message is important for ensuring that the server can properly interpret and respond to the client’s request.