WordPress provides comment feature. Website needs comment section for reviews which makes visitor engagement on web page.
You can change the look and feel of the comment section. In default WordPress themes we have comment.php which is responsible to make the changes in comment section. Bydefault comment.php looks like this.

<?php
/**
 * The template for displaying Comments
 *
 * The area of the page that contains comments and the comment form.
 *
 * @package WordPress
 * @subpackage Twenty_Thirteen
 * @since Twenty Thirteen 1.0
 */

/*
 * If the current post is protected by a password and the visitor has not yet
 * entered the password we will return early without loading the comments.
 */
if ( post_password_required() )
    return;
?>

<div id="comments" class="comments-area">

    <?php if ( have_comments() ) : ?>
        <h2 class="comments-title">
            <?php
                printf( _nx( 'One thought on &ldquo;%2$s&rdquo;', '%1$s thoughts on &ldquo;%2$s&rdquo;', get_comments_number(), 'comments title', 'twentythirteen' ),
                    number_format_i18n( get_comments_number() ), '<span>' . get_the_title() . '</span>' );
            ?>
        </h2>

        <ol class="comment-list">
            <?php
                wp_list_comments( array(
                    'style'       => 'ol',
                    'short_ping'  => true,
                    'avatar_size' => 74,
                ) );
            ?>
        </ol><!-- .comment-list -->

        <?php
            // Are there comments to navigate through?
            if ( get_comment_pages_count() > 1 && get_option( 'page_comments' ) ) :
        ?>
        <nav class="navigation comment-navigation" role="navigation">
            <h1 class="screen-reader-text section-heading"><?php _e( 'Comment navigation', 'twentythirteen' ); ?></h1>
            <div class="nav-previous"><?php previous_comments_link( __( '&larr; Older Comments', 'twentythirteen' ) ); ?></div>
            <div class="nav-next"><?php next_comments_link( __( 'Newer Comments &rarr;', 'twentythirteen' ) ); ?></div>
        </nav><!-- .comment-navigation -->
        <?php endif; // Check for comment navigation ?>

        <?php if ( ! comments_open() && get_comments_number() ) : ?>
        <p class="no-comments"><?php _e( 'Comments are closed.' , 'twentythirteen' ); ?></p>
        <?php endif; ?>

    <?php endif; // have_comments() ?>

    <?php comment_form(); ?>

</div><!-- #comments -->