HTTP 1xx Codes or HTTP 1xx Information Codes don't represent the final status of the request made, they are messages intended to share the information about the connection.
There are four main types of HTTP 1xx Codes, these four types are listed below.
Table of Contents
100 Continue
The 100 Continue means that the client should continue with it's request. The server returns this response code to inform that it has received the request headers from client, and it is confirmation of the initial request, to the client, so that it may send the response body.
101 Switching Protocols
The 101 Switching Protocols means that the client has asked the server to switch protocols and the server has accepted the client’s request to switch the protocols.
102 Processing
The 102 Processing means that the server has received client's response and now it is taking sometime to process the request. This code is sent to the client so that it doesn't think that the request is lost.
103 Checkpoint
The 103 Checkpoint is used in response to the resumable requests proposal, to resume the aborted PUT or POST requests.