When a request is sent to a server, the first line that
is expected from the server is called the Status line. It
describes the server's behavior based on our request.
It has two parts: status number, and status text.
The user should ignore this value if a document was
received successfully. If a document is not received, this
information should reveal the reason for the document
retrieval failure.
Typically, this will look like '200
OK' if no error occurred, or i.e. '404 File not found' if file was not
found on the server.