For posts (category)
| get_object_taxonomies() | Gets the taxonomies related to the specified post type or the passed object. |
| get_objects_in_term() | Gets the IDs of objects (usually posts) that relate to the specified element of the specified taxonomy. |
| get_the_category() | Gets an array of categories data related to current post. |
| get_the_category_list() | Retrieve links to the categories to which the post belongs in either HTML list or custom format. |
| get_the_tag_list() | Gets the HTML string of tags for the current post. The name of each tag will be a link to the archive of posts with that tag. Used in a loop. |
| get_the_tags() | Retrieve an array of post tags. Each array element is a WP_Term object. Can be used within The Loop. |
| get_the_taxonomies() | Retrieve all taxonomies associated with a post. Gets an array of HTML links. |
| get_the_term_list() | Displays a list of links to taxonomy elements (e.g. tags) related to a specified post. |
| get_the_terms() | Gets the taxonomy elements (terms) that are attached to the specified post. |
| has_category() | Checks whether the current or specified post has at least one of the specified categories. |
| has_tag() | Checks if the current post has any of the given tags. A conditional tag. |
| has_term() | Checks if the specified post is associated with the specified taxonomy terms. |
| is_object_in_taxonomy() | Checks if the specified post type is associated with the specified taxonomy. |
| is_object_in_term() | Defines whether the specified object is associated with any of the specified taxonomy elements (term). Specific term(s) can be provided to check the association. |
| the_category() | Displays links to the categories to which the post belongs in either HTML list or custom format. |
| the_tags() | Retrieve the tags links for a post. |
| the_taxonomies() | Display links to taxonomy terms of the current post. Used inside WordPress loop |
| wp_delete_object_term_relationships() | Destroys all relationships of the object (post, page) with the specified taxonomy(ies). |
| wp_get_object_terms() | Gets the terms (taxonomy elements) related to the given object(s) (posts) in the specified taxonomy. |
| wp_get_post_categories() | Gets the list of post categories as an array. |
| wp_get_post_tags() | Gets a list of tags for a specified post as an array. |
| wp_get_post_terms() | Gets the elements of the specified taxonomy (tag, category) to which specified post is associated. |
| wp_remove_object_terms() | Breaks the connection between the specified object and the specified term, i.e., removes the post from the taxonomy element (category). |
| wp_set_object_terms() | Attaches a post to a term (taxonomy element). For example, places a post in the specified category. |
| wp_set_post_categories() | Sets categories for a post. |
| wp_set_post_tags() | Sets tags for a post. |
| wp_set_post_terms() | Sets the terms for specified post (sets categories for post). |