Answers for "strings \r\n meaning in php"

newline in php

<?php
 echo nl2br("If you want that '\n' works. \n Then use nl2br() function!");
 echo "<br> can also be used.";
 echo "nl2br() is in-built function whereas <br> is html tag";
?>

\r in php

They're "carriage return" and "line feed" respectively. Typically on Windows, you need both together to represent a line terminator: "\r\n" whereas on most (all?) Unix systems, "\n" is enough.