What use function hook_entity_access In drupal 9

<?php

use Drupal\Core\Access\AccessResult;
 
...
 
/**
 * Implements hook_entity_access().
 */
function drupalbook_examples_entity_access(\Drupal\Core\Entity\EntityInterface $entity, $operation, \Drupal\Core\Session\AccountInterface $account) {
  if ($entity->getEntityTypeId() == 'node' && $entity->getType() == 'article' && $operation == 'view' && in_array('administrator', $account->getRoles())) {
    AccessResult::forbidden();
  }
}

?>

There Main Three types AccessResult as Below 

1. return AccessResult::allowed();  - This one give Almost all permission line CRUD.
    
2. return AccessResult::neutral(); - This One give Only View Node or entity.
    
3. return AccessResult::forbidden(); - This give you access denied.

Entity Access Is used if you want to give some specific access to any specific role at that time you can use this.