An HTTP request asks for an HTTP resource from a server. An HTTP request includes the request URL (the resource the client is trying to access), the HTTP method (GET, POST, etc.), and optionally form parameter data (query string). In a request body, user-entered data or uploaded files are sent to the server.
The format of the request message consists of:
- an initial line
- zero or more header lines
- a blank line (i.e. a CRLF by itself), and
- an optional message body