5XX:

500 – Internal Server Error – It comes when an unexpected condition was encountered and no more specific message is suitable to show.

501 – Not Implemented – The server does not support the facility required. Here server lacks the ability to fulfill the request.

502 – Bad Gateway – The server was acting as a gateway or proxy and received an invalid response from the upstream server

503 – Service Unavailable/Out of Resources – The server is currently unavailable and not able to process the request.

504 – Gateway Timeout – The service did respond within the time frame that the gateway was willing to way.

505 – HTTP Version Not Supported – The server does not support the HTTP protocol version used in the request.

3XX:

300- Multiple Choices – Here user can select a link and go to different locations. It shows different options of resources that the client may follow. It could take maximum five addresses. Its example could be like that it can open file in different extensions or it can show different format option for video file.

301- Moved Permanently – The requested page has been moved to a new address or URL and in the future it should be directed to this given URL.

302 – Found/Moved Temporarily – The requested page has been moved temporarily to the new URL.

303- See Other – The requested page can be found under another URL i.e. the response of the request can be found under another URL.

304 –Not Modified –This indicates that the requested page i.e. the resource has not been modified since the last request has been made. The cached version of the resource is same as the file is requested.

305 – Use Proxy – The requested resource or page is only available through a proxy, whose address is provided in the response. There are many clients which do not correctly handle the response of the requests according to the status code due to securing reasons.

307 – Temporarily Redirect – The requested page has moved temporarily to a new URL.

1XX:

100 – Continue -The request header has been received by the server correctly and client can continue to send the request body.

101 – Switch the Protocol- The client has requests the server to switch the protocol and server is responding in positive manner.

102 – In Process -Due to this code, it indicates that the server has received the request from the client and processing the request but response is yet not available. Due to this client does not get timed out and it is assumed that the request was lost.

2XX:

200 – OK – Request is sent and the response is successful.

201 – Created- The request has been fulfilled and due to this new resource being created.

202 – Accepted –The request has be accepted but for processing, but the processing has not been completed yet.

203 – Partial or Non-Authoritative Information – The request has been successfully processed but the information sent in the response is might be from another source.

204 – No Content – The request has been successfully processed but in the response it is not sending any content.

205 – Reset Content – The request has been successfully processed but the server is not returning any content in the response. It requires that the requester reset the document view.

206 – Partial Content – The file in the request was partially sent. This happened generally due to web page has been stopped or refreshed. Due to this server would deliver only few part of resource in the response.

The Web Services Description Language is an XML-based interface definition language that is used for describing the functionality offered by a web service. The acronym is also used for any specific WSDL description of a web service (also referred to as a WSDL file).

Both JSON and XML can be used to receive data from a web server.

CONNECT
Establishes a tunnel to the server identified by a given URI.
OPTIONS
Describes the communication options for the target resource.
HEAD
Same as GET, but transfers the status line and header section only.
GET
The GET method is used to retrieve information from the given server using a given URI.

4XX:

400 – Bad Request – The request cannot be fulfilled due to syntax error.

401 – Unauthorized – Valid request is made to the server but the server refused to respond due to authentication error. It could be due to invalid user name or password provided for login into page.

402 – Payment required – This is stored for the future use.

403 – Forbidden – The server is refusing to respond for the request as the request made is valid.

404 – Not Found – The requested page is not found now but it may be available in the future.

405 – Method Not Allowed – The request is made to the page or resource using method but that method is not supported by page or resource.

406 – Not Acceptable – The server can only generate a response that is not accepted by the by the client.

407 – Proxy Authentication required – Here the client must authenticate with the proxy first.

408 – Request Timeout – The server timed out waiting for the request.

409 – Conflict – The request could not be processed or completed because of the conflict in the request.

410 – Gone – This indicates that the page or resource requested is no longer available now.

411 – Length required – The request could not be processed by the server as the content length in the request is not defined.

412 – Precondition Failed – Here server does not meet any of the preconditions that the requester put in the request.

413 – Request Entity Too Large – Request content is so large that server is not able to process the request.

414 – Request URL Too Large – The server will not accept the request as the URL is too long. Due to this server is not able to process the request.

415 – Unsupported Media Type – The server is not able to process the request as the media type is not supported by the request.

416 – Request Range Not Satisfiable – This is due to that client has asked for the portion of the file but server is not able to supply that portion of the file to the client.

JSON: JavaScript Object Notation.
JSON is a syntax for storing and exchanging data.
JSON is text, written with JavaScript object notation.

REST stands for Representational State Transfer. (It is sometimes spelled “ReST”.) It relies on a stateless, client-server, cacheable communications protocol