How add multi-type custom functionality in wordpress site

Add these all in your function.php file under in your theme folder. /*******User permission Section Start here *********/ /* Fire our meta box setup function on the post editor screen. */ add_action( ‘load-post.php’, ‘smashing_post_meta_boxes_setup’ ); add_action( ‘load-post-new.php’, ‘smashing_post_meta_boxes_setup’ ); /* Meta box setup function. */ function smashing_post_meta_boxes_setup() { /* Add meta boxes on the ‘add_meta_boxes’ …