How do I query a custom post type with a custom taxonomy?

Query post type by specials taxonomy slug

$the_query = new WP_Query( array(
    'post_type' => 'Adverts',
    'tax_query' => array(
        'taxonomy' => 'advert_tag',
        'field' => 'slug',
        'terms' => 'politics',
    ),
) );

while ( $the_query->have_posts() ) :
    $the_query->the_post();
    // Show Posts ...
endwhile;

/* Restore original Post Data 
 * NB: Because we are using new WP_Query we aren't stomping on the 
 * original $wp_query and it does not need to be reset.
*/
wp_reset_postdata();

Query post type by specials taxonomy id

$query = new WP_Query( array(
    'post_type' => 'faqs',          // name of post type.
    'tax_query' => array(
        array(
            'taxonomy' => 'faq_category',   // taxonomy name
            'field' => 'term_id',           // term_id, slug or name
            'terms' => 48,                  // term id, term slug or term name
        )
    )
) );

while ( $query->have_posts() ) : $query->the_post();
    // do stuff here....
endwhile;

/**
 * reset the orignal query
 * we should use this to reset wp_query
 */
wp_reset_query();