WordPress provides us four type of action:
{taxonomy_name}_add_form_fields => to add fields in taxonomy create form
{taxonomy_name}_edit_form_fields => to add fields in taxonomy edit form
edited_{taxonomy_name} => to process edit form fields
create_{taxonomy_name} => to process create form fields
manage_edit-{taxonomy_name}_columns => to register custom column for admin screen
manage_{taxonomy_name}_custom_column => to populate content of custom column in admin screen
What is {taxonomy_name}?
In WordPress, a taxonomy is a means of organizing (or categorizing) something. WordPress posts are configured by default with two taxonomies: “categories” and “tags”. The values you create within those categories are known as its “terms”. So {taxonomy_name} stands for the slug that is associated with the taxonomy, for example: Post Categories => category, Post Tag => post_tag, Woo Product Categories => product_cat, Woo Product Tags => product_tag, etc..