A status code of 100 indicates that (usually the first) part of a request has been received without any problems, and that the rest of the request should now be sent.
'''101 - Switching Protocols'''
HTTP 1.1 is just one type of protocol for transferring data on the web, and a status code of 101 indicates that the server is changing to the protocol it defines in the "Upgrade" header it returns to the client. For example, when requesting a page, a browser might receive a statis code of 101, followed by an "Upgrade" header showing that the server is changing to a different version of HTTP.
