List of post of a category can be show using wp_query like this
$paged = get_query_var('paged') ? get_query_var('paged') : 1;
$args = array(
'post_type' => 'post', //Specifying post type
'posts_per_page' => 10, //How many posts per page
'cat' =>'cat2', //Specifying post category to show posts
'paged' => $paged //For pagingation (if required)
);
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
?>
<h3><?php the_title();?></h3>
<?php
endwhile; ?>