Here is a list of the result codes that can be returned in response to an HTTP request:

200 - OK, successful transmission. This is not an error.

302 - Redirection to a new URL. The original page has moved. This is not an error; most browsers invisibly fetch the new page upon seeing this result.

304 - Use local copy. This means that the copy of the file on the web server is not newer than the copy which your web browser or proxy server has cached locally, so there's no point in sending the file again. This is not an error.

401 - Unauthorized. The user asked for a document but did not provide a valid username or password.

403 - Forbidden. Access is explicitly denied to this document. (This might happen because the web server doesn't have read permission for the file you're requesting.)

404 - Not found. This can also be sent if the server has been told to protect the document by telling unauthorized people that it doesn't exist.

500 - Server error. Something went wrong with the web server and it couldn't give you a meaningful response. There is usually nothing that can be done from the browser end to fix this error; the server administrator will probably need to check the server's error log to see what happened.