What does HTTP status code 200,300,404 mean?

You should know the status code when learning Web design, but our common status code is 200,404, the following describes the other status values

1 HTTP status code starting with
A status code that represents a temporary response and requires the requestor to continue the operation.

100 (continued) The requesting person shall continue to make the request. The server returns this code to indicate that the first part of the request was received and is waiting for the remainder.
101 (switching protocol) The requestor has asked the server to switch protocols, and the server has confirmed and is ready to switch.

2 HTTP status code starting with
Indicates a successful request

200 successfully processed the request, usually return this status code;
201 the request was successful and the server created a new resource.
202 accepting requests but not creating resources;
203 a request to return another resource;
204 The server successfully processed the request, but did not return any content;
205 The server successfully processed the request, but did not return any content;
206 processing part of the request;

3XX (redirected)
Redirect Code, also common code

300 (multiple options) for requests, the server can perform a variety of operations. The server can select an action based on the requestor (user agent) or provide a list of actions for the requestor to select.
301 (permanently moved) The requested page has been permanently moved to a new location. When the server returns this response (a response to a GET or HEAD request), the requestor is automatically forwarded to the new location.
302 (Temporary move) The server is currently responding to requests from a Web page in a different location, but the requestor should continue to use the original location for future requests.
303 (View other locations) The server returns this code when the requestor should use a separate GET request for the different locations to retrieve the response.
304 (not modified) The requested webpage has not been modified since the last request. When the server returns this response, the Web page content is not returned.
305 (using a proxy) the requestor can only use the proxy to access the requested Web page. If the server returns this response, it also indicates that the requestor should use the proxy.
307 (Temporary redirect) The server is currently responding to requests from a Web page in a different location, but the requestor should continue to use the original location for future requests.


4 Initial HTTP status code indicates a request error

400 the server does not understand the syntax of the request.
401 Request Authentication required. The server may return this response for pages that need to log on.
403 The server denied the request.
404 the server could not find the requested Web page.
405 disables the method specified in the request.
406 The requested content attribute cannot be used to respond to the requested Web page.
407 This status code is similar to 401, but specifies that the requestor should authorize the use of the proxy.
408 A timeout occurred while the server was waiting for a request.
409 The server has a conflict while completing the request. The server must include information about the conflict in the response.
410 The server returns this response if the requested resource has been permanently deleted.
411 The server does not accept requests that do not contain a valid Content-Length header field.
412 The server does not meet one of the prerequisites set by the requestor in the request.
413 The server cannot process the request because the request entity is too large to exceed the processing power of the server.
414 The requested URI (usually the URL) is too long for the server to process.
415 the requested format is not supported by the requested page.
416 If the page cannot provide the requested range, the server returns this status code.
417 the server does not meet the requirements for the "expected" Request header field.


5 The initial status code is not common, but we should know

500 (server internal error) the server encountered an error and could not complete the request.
501 (not yet implemented) the server does not have the capability to complete the request. For example, this code may be returned when the server does not recognize the request method.
502 (Error Gateway) The server receives an invalid response from the upstream server as a gateway or proxy.
503 (Service Unavailable) the server is not currently available (due to overloading or downtime maintenance). Typically, this is only a temporary state.
504 (Gateway Timeout) The server acts as a gateway or proxy, but does not receive requests from the upstream server in a timely manner.
505 (HTTP version not supported) the HTTP protocol version used in the request is not supported by the server.

What does HTTP status code 200,300,404 mean?