These are the definitions of result codes that can be returned in response to a HyperText Transfer Protocol (HTTP) request:

• 200 - Successful transmission. This is not an error.
  
  
• 302 - Redirection to a new Uniform Resouce Locator(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. The file stored in cache (either a Proxy cache or a browser cache) is newer than the file stored on the server. 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 being requested.
  
  
• 404 - Not found. In some cases, the file actually exists but the server is protecting it by telling an unauthorized user that the file does not exist.
  
  
• 500 - Server error. Something went wrong with the web server and it couldn't give you a meaningful response. There is nothing that can be done from the browser to fix this error, the server administrator will need to check the server's error log for more details on the error .