is_singular()

is_singular() — Determines whether the query is for an existing single post of any post type (post, attachment, page, custom post types). If the $post_types parameter is specified, this function will additionally check if the query is for one of the Posts Types specified. For more information on this and similar theme functions, check out the {

Inputs: $post_types (string|string[]): Optional. Post type or array of post types to check against. Default empty.

Returns bool: Whether the query is for an existing single post or any of the given post types.