Delete operation in Drupal 7

The following function is used to delete file and file usage in Drupal 7.
file_data($file);

The following db function is used to delete a record from a table in Drupal 7.
db_delete('table')->condition('field', $value->execute();

The following drupal function is used to delete a node in Drupal 7.
node_delete($nid);
Multiple node delete: node_multiple_delete(array($nid1, $nid2));

The following drupal function is used to delete a user in Drupal 7.
user_delete($uid);
Multiple user delete: user_multiple_delete(array($uid1, $uid2));

The following drupal function is used to delete a content type in Drupal 7.
node_type_delete($type);