What is Orphan?

Hello. I tried to plugin but I do not understand. Look please

http://i.imgur.com/0qJaBHb.jpg

What is Orphan Relationships? and

what is Dashboard Transient Feed?

$wcu_sql = “DELETE FROM $wpdb->term_relationships WHERE term_taxonomy_id=1 AND object_id NOT IN (SELECT id FROM $wpdb->posts)”;

$wcu_sql = “DELETE FROM $wpdb->options WHERE option_name LIKE ‘_site_transient_browser_%’ OR option_name LIKE ‘_site_transient_timeout_browser_%’ OR option_name LIKE ‘_transient_feed_%’ OR option_name LIKE ‘_transient_timeout_feed_%'”;

why taxonomy? (tags? category?)

thanks

http://wordpress.org/extend/plugins/wp-clean-up/