PHP

wordpress get taxonomy of a post

//Get all terms (names) of a taxonomy of a post
$term_obj_list = get_the_terms( $post->ID, 'taxonomy_name' ); ?>

wordpress get post taxonomy terms

//Get selected terms of a post by taxonomy
$selectedTerms = wp_get_post_terms(get_the_ID(),'TAXONOMY_NAME');
foreach($selectedTerms as $term){
	echo $term->name;
}

wordpress get terms by taxonomy

You need to pass an additional argument to get_terms(). The default is to hide
"empty" terms-- terms which are assigned to no posts.

$terms = get_terms([
    'taxonomy' => $taxonomy,
    'hide_empty' => false,
]);

get post by taxonomy

<?php
     $taxonomy = 'my_taxonomy'; // this is the name of the taxonomy
     $terms = get_terms($taxonomy);
     $args = array(
        'post_type' => 'post',
        'tax_query' => array(
                    array(
                        'taxonomy' => 'updates',
                        'field' => 'slug',
                        'terms' => wp_list_pluck($terms,'slug')
                    )
                )
        );

     $my_query = new WP_Query( $args );
     if($my_query->have_posts()) :
         while ($my_query->have_posts()) : $my_query->the_post();

              // do what you want to do with the queried posts

          endwhile;
     endif;
  ?>

get post by taxonomy

foreach ($myterms as $term) :

$args = array(
    'tax_query' => array(
        array(
            $term->slug
        )
    )
);

//  assigning variables to the loop
global $wp_query;
$wp_query = new WP_Query($args);

// starting loop
while ($wp_query->have_posts()) : $wp_query->the_post();

the_title();
blabla....

endwhile;

endforeach;