need code detail

Hi,
I need where this code located in twentytwele theme.
1) <div class=”nav-previous”><?php next_posts_link( __( ‘<span class=”meta-nav”>←</span> Older posts’, ‘twentyten’ ) ); ?></div>

2) <?php wp_link_pages( … ); ?>

Thanks in advance
b.Paramaguru

https://ww.wp.xz.cn/plugins/wp-paginate/