Display an archives name

This is probably what you need:

<?php if (is_category()) { // Show only on Category archive pages ?>
<h1><?php echo single_cat_title('News: '); ?></h1>

<?php } elseif (is_tag()) { // Show only on Tag archive pages ?>
<h1><?php echo single_tag_title('News: '); ?></h1>

<?php } ?>

OR like this (as @StephenHarris pointed out):

<h1><?php
    if ( is_category() || is_tag() ) {
        single_term_title( 'News: ', false );
    }
?></h1>