There is no difference whatsoever. What is important is the
101 response code to indicate the handshake is progressing.
This is defined in RFC
The leading line from the client follows the Request-Line format.
The leading line from the server follows the Status-Line
format. The Request-Line and Status-Line productions are defined
The handshake from the server is much simpler than the client
handshake. The first line is an HTTP Status-Line, with
the status code 101:
HTTP/1.1 101 Switching Protocols
Any status code other than 101 indicates that the WebSocket handshake
has not completed and that the semantics of HTTP still apply.
The text of the
Status-Line is arbitrary, the server can
use whatever text it wants, per RFC 2616:
Status-Line = HTTP-Version SP Status-Code SP
The Status-Code element is a 3-digit integer result code of the
attempt to understand and satisfy the request. These codes are fully
defined in section 10. The Reason-Phrase is intended to give a short
textual description of the Status-Code. The Status-Code is intended for use
by automata and the Reason-Phrase is intended for the human user.
The client is not required to examine or display the
Switching Protocols just happens to be what the examples in
RFC 6455 use, but that is
not a requirement.