How to Add 'Post Categories' to the Dashboard Sidebar

Question

I'm currently working with a company to make a few basic tweeks to their WordPress site and I noticed that they have this on their sidebar:

I am looking particularly at the "Clients", "Offers", "Portfolio" and "Slider Offer" sections, I have never seen these before and believe that they have not been added with a plugin. It appears that they are post categories, as they have the same pin icon as the "Posts" section. Can anyone explain what these are, how they work and how to add them?

Thanks

Answer 1

WordPress Core post types are post and page that are visible in the admin menu. Other than these can be either a registered custom post type or a menu page.

A menu page can be added with the add_menu_page() function, and a similar thing can be done using register_post_type(), where a registered post type gets its own menu item where the following arguments are true:

<?php
$args = array(
        'show_ui'   => true,
        'show_in_menu' => true
    );

register_post_type( 'mycpt', $args );

Note that, register_post_type() is a plugin-territory function. But some themes include them into their functions.php. And in that case, it's also possible, a parent theme didn't include 'em, but a child theme did so into its functions.php. :)

Answer 2

I Believe this are the Custom Post type of wordpress. Custom post type will work in same way as the post is working, you can make different category for each post type and also will able to create different archive and single page. I am posting a sample post type code if you want to experiment more on this. This code you simply copy and past into function.php of your theme or you can put this in different .php file and you can require_once in function.php file like i am doing require_once('custom-post-type/team.php'); I always create different folder of custom post type and then put all post type files there and make it require in function file.

<?php
/* Custom Post Type ===> team_member */
add_action( 'init', 'register_cpt_team_member' );
function register_cpt_team_member() {
$labels = array( 
    'name' => _x( 'Team Member', 'team_member' ),
    'singular_name' => _x( 'Team Member', 'team_member' ),
    'add_new' => _x( 'Add New', 'team_member' ),
    'add_new_item' => _x( 'Add New Team Member', 'team_member' ),
    'edit_item' => _x( 'Edit Team Member', 'team_member' ),
    'new_item' => _x( 'New Team Member', 'team_member' ),
    'view_item' => _x( 'View Team Member', 'team_member' ),
    'search_items' => _x( 'Search Team Member', 'team_member' ),
    'not_found' => _x( 'No Team Member found', 'team_member' ),
    'not_found_in_trash' => _x( 'No Team Member found in Trash', 'team_member' ),
    'menu_name' => _x( 'Team Member', 'team_member' ),
);
$args = array( 
    'labels' => $labels,
    'hierarchical' => false,       
    'supports' => array( 'title', 'editor', 'author', 'thumbnail', 'custom-fields', 'revisions', 'page-attributes' ),
    //'taxonomies' => array('post_tag'),
    'public' => true,
    'show_ui' => true,
    'show_in_menu' => true, 
    'menu_icon' => 'dashicons-admin-users',     
    'show_in_nav_menus' => true,
    'publicly_queryable' => true,
    'exclude_from_search' => false,
    'has_archive' => true,
    'query_var' => true,
    'can_export' => true,
    'rewrite' => array('slug' => 'team_member'),
    'capability_type' => 'post'
);
register_post_type( 'team_member', $args );
flush_rewrite_rules(); // <- do this only once!
}
?>

If you want to Know more details on custom post type refer to wordpress codex. https://codex.wordpress.org/Post_Types