# HTTP

## Request Methods

Common and often used HTTP request methods you should know. Read more [here](https://httpwg.org/specs/rfc9110.html#methods).

<table><thead><tr><th width="198">Method</th><th>Description</th></tr></thead><tbody><tr><td>GET</td><td>Send named resource from the server to the client.</td></tr><tr><td>HEAD</td><td>Send just the HTTP headers from the response for the named resource.</td></tr><tr><td>POST</td><td>Send client data into a server gateway application.</td></tr><tr><td>PUT</td><td>Store data from client into a named server resource.</td></tr><tr><td>DELETE</td><td>Delete the named resource from a server.</td></tr></tbody></table>

## Status Codes

Common and often used HTTP status codes you should know. Read more [here](https://httpwg.org/specs/rfc9110.html#status.codes).

### 2xx

These status codes indicate that the request was successfully received, understood, and accepted.

<table><thead><tr><th width="225">Code</th><th>Description</th></tr></thead><tbody><tr><td>200 OK</td><td>Standard response for successful HTTP requests.</td></tr><tr><td>201 Created</td><td>The request succeeded and a new resource was created. Often used after a successful <code>POST</code> request.</td></tr><tr><td>204 No Content</td><td>The request succeeded but no content was returned. Might be used after a successful <code>DELETE</code> request.</td></tr></tbody></table>

### 3xx

These status codes indicate a redirection and that further action needs to be taken by the user agent in order to fulfill the request.

| Code                  | Description                                                                                                 |
| --------------------- | ----------------------------------------------------------------------------------------------------------- |
| 301 Moved Permanently | The URL of the requested resource has been changed permanently and the new URL is provided in the response. |
| 304 Not Modified      | The response was cached and has not been modified.                                                          |

### 4xx

These status codes indicate that there occured an error on the client side.

<table><thead><tr><th width="232">Code</th><th>Description</th></tr></thead><tbody><tr><td>400 Bad Request</td><td>The server cannot process the received request from the user. For example if a form value is invalid.</td></tr><tr><td>401 Unauthorized</td><td>Equivalent to "unauthenticated". The client must authenticate itself. For example via <a href="https://jwt.io/">JWT</a>.</td></tr><tr><td>403 Forbidden</td><td>The client does not have access rights to the content.</td></tr><tr><td>404 Not Found</td><td>The requested resource does not exist on the server side.</td></tr></tbody></table>

### 5xx

These status codes indicate that there occured an error on the server side.

| Code                      | Description                                                                    |
| ------------------------- | ------------------------------------------------------------------------------ |
| 500 Internal Server Error | The server encountered an unexpected condition and cannot fulfill the request. |

## Further Resources

Read more here:

* [RFC 9110](https://httpwg.org/specs/rfc9110.html#top)
* [HTTP: The Definitive Guide](https://www.oreilly.com/library/view/http-the-definitive/1565925092/)