Please help the moderator, ask what this means?

Please help the moderator, what does this mean??
Header (' Www-authenticate:basic realm = ' realm-name ');
Header (' status:401 unauthorized ');
Header (' http/1.0 401 Unauthorized ');
Header ("location:http://www.example.com/");
Header (' www-authenticate:negotiate ');
Header (' WWW-AUTHENTICATE:NTLM ', false);
What do you mean by these few? Often see in PHP oh, I read in the PHP manual, still do not quite understand. Please advise. Thank you.
------Solution--------------------
http://www.php.net//manual/zh/function.header.php
------Solution--------------------
Header (' Www-authenticate:basic realm = ' realm-name ');
This is used to verify that the login, will pop a box to the user number mega code, enter the mega and password can pass through
$_server[' Php_auth_user '];
$_server[' PHP_AUTH_PW '];
Access to the line of judgment


Header (' status:401 unauthorized ');
Header (' http/1.0 401 Unauthorized ');
These two sentences output state value (401) to the browser, which is used primarily for access rights control.


Header ("location:http://www.example.com/");
page 302 Redirect to http://www.example.com


Header (' www-authenticate:negotiate ');
Set up a text message

Header (' WWW-AUTHENTICATE:NTLM ', false);
Set a report message because the back side is false and does not cover the previous negotiate, so the two text messages coexist

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