Often one can observe that, instead of the requested page your browser displays a white sheet with black lettering and three-digit number. What does this mean? This server is requested site (pages) gives an error HTTP. These errors are different. We explain the main ones. 300 (Multiple Choices or several options to choose from) means that the requested IP address has several resources.
For example, one and the same instrument, but with translations into other languages. 301 (Moved Permanently moved or Resource always) means that the requested address is moved permanently, and the server it no longer uses. The new address can be specified in the Location header. 302 (Moved Temporarily or Resource temporarily moved) Indicates that the requested address is moved temporarily server and it no longer uses. The new address can be specified in the Location header. 303 (See Other See or other resource) means that the requested IP address can be found at another location. The address can be specified in the Location header. 304 (Not Modified or not changed) Means that the address has not changed with the title lf-Modified-Since date.
Then the body is not changed and is the local version of the document. 305 (Use Proxy, or use a proxy server) means that you must use a proxy server. Its address indicated in the Location header. 400 (Bad Request or Invalid Request) means that the server did not understand request. 401 (Unauthorized or no resolution) means that no authenticated user. Response includes the header WWW-Authenticate, which contains challenge to the resource request.