perl小白，谁能帮忙给个详细解释

check.cgi

 #!/usr/local/bin/perl -Tw

use strict;
use CGI;

my($cgi) = new CGI;

print $cgi->header('text/html');
print $cgi->start_html(-title => "Example CGI script",
                       -BGCOLOR => 'red');
print $cgi->h1("CGI Example");
print $cgi->p, "This is an example of CGI\n";
print $cgi->p, "Parameters given to this script:\n";
print "<UL>\n";
foreach my $param ($cgi->param)
{
 print "<LI>", "$param ", $cgi->param($param), "\n";
}
print "</UL>";
print $cgi->end_html, "\n";

color.cgi

 #!/usr/local/bin/perl -Tw

use strict;
use CGI;

my($cgi) = new CGI;

print $cgi->header;
my($color) = "blue";
$color = $cgi->param('color') if defined $cgi->param('color');

print $cgi->start_html(-title => uc($color),
                       -BGCOLOR => $color);
print $cgi->h1("This is $color");
print $cgi->end_html;

哪位大神能到上面两段perl代码详细讲讲啊
我C币不都多！

例子程序，演示给html元素增加参数