These type of errors 400, 401 - 404, 501 - 503, etc are supposed to be the HTTP status codes. Such a kind of responses occur when a request is been made to the server to access a page on your site. This specification occur when you're not able to get the response that you want.
301 - Redirects errors to either a custom error page, or some other page in the site. 403 is HTTP error. The request requires user authentication. These type of errors 400, 401 - 404, 501 - 503, etc are supposed to be the HTTP status codes
301 - Redirects errors to either a custom error page, or some other page in the site.
403 is HTTP error. The request requires user authentication.
These type of errors 400, 401 - 404, 501 - 503, etc are supposed to be the HTTP status codes.