HTTP status codes are three-digit responses from the server to the browser that indicates the status of the request. It is divided into 5 different categories, each category represents a different kind of status

1XX: Information

Is a temporary status code which means that the server has received the request and is continuing the process

100 Continue

101 Switching Protocols

102 Processing request

103 Early Hints

2XX: Success

Means that the request was successful and the browser has received the expected information

200 OK

201 Created

202 Accepted

203 Non-Authoritative Information

204 No Content

205 Reset Content

206 Partial Content

207 Multi-Status

208 Already Reported

226 IM Used

3XX: Redirection

The type of status means you have been redirected and the completion of the request requires further action, not necessarily from your side

300 Multiple Choices

301 Moved Permanently

302 Found

303 See Other

304 Not Modified

305 Use Proxy

306 Switch Proxy

307 Temporary Redirect

308 Permanent Redirect

4XX: Client Error

When the website or the page could not be reached and either the page is unavailable or the request contains bad syntax

400 Bad Request

401 Unauthorized

402 Payment Required

403 Forbidden

404 Not Found

405 Method Not Allowed

406 No Acceptable

407 Proxy Authentication Required

408 Request Timeout

409 Conflict

410 Gone

411 Length Required

412 Precondition Failed

413 Payload Too Large

414 URI Too Long

415 Unsupported Media Type

416 Range Not Satisfiable

417 Expectation Failed

418 I'm a Teapot

421 Misdirected Request

422 Unprocessable Entity

423 Locked

424 Failed Dependency

425 Too Early

426 Upgrade Required

428 Precondition Required

429 Too Man Requests

431 Request Header Fields Too Large

451 Unavailable For Legal Reasons

5XX: Server Error

While the request might be valid, the server could not complete the request. These kinds of errors are mostly caused due to problems internally within server

500 Internal Server Error

501 Not Impemented

502 Bad Gateway

503 Service Unavailable

504 Gateway Timeout

505 HTTP Version Not Supported

506 Variant Also Negotiates

507 Insufficient Storage

508 Loop Detected

510 Not Extended

511 Network Authentication Required

Finally, you may not need to memorize all of these status codes, but it's always good to know most of them, and organize your API responses as clear as possible