HTTP Status Codes Explained for Most Folks
There are lots of jokes about HTTP status codes, what they mean, and general frustration with the inconsistent way in which they're used.
HTTP 1xx
- 100: Continue sending me the request.
HTTP 2xx
- 200: OK, here you go.
- 201: OK, I created it for you.
HTTP 3xx
- 301: Moved what you want to a new spot over here.
- 302: Found what you're looking for over here.
HTTP 4xx
- 400: Your bad.
- 401: You aren't logged in.
- 403: You're logged in, but can't do/see that.
HTTP 5xx: Our bad
- 500: We screwed up.
- 503: We forgot to start the server.
There are many more status codes, and as a developer I encourage other developers to use appropriate and specific response codes. For more specific details, Wikipedia has a good overview.