my $qqstring = <<"HERE";
This text is subject to double-quoted interpolation.  It can include escapes like \t, and $variables.
HERE
my $string = <<HERE;
This text is also subject to double-quoted interpolation.
HERE
my $qstring = <<'HERE';
This text is treated like a single-quoted string, except that it can contain embedded single quotes.  \t is just a backslash followed by a 't', and $variables is just a dollar sign followed by the string 'variables'.
HERE