You can use <?php get_template_part( $slug, $name ); ?>
http://codex.wordpress.org/Function_Reference/get_template_part
or a PHP include <?php include("file.php"); ?>
You can use <?php get_template_part( $slug, $name ); ?>
http://codex.wordpress.org/Function_Reference/get_template_part
or a PHP include <?php include("file.php"); ?>