diff --git a/core/lib/Drupal/Core/Entity/EntityEvent.php b/core/lib/Drupal/Core/Entity/EntityEvent.php
index 539f6d6..f504666 100644
--- a/core/lib/Drupal/Core/Entity/EntityEvent.php
+++ b/core/lib/Drupal/Core/Entity/EntityEvent.php
@@ -5,11 +5,16 @@
 use Symfony\Component\EventDispatcher\Event;
 
 /**
- * @todo.
+ * Represents various entity events.
+ *
+ * @see \Drupal\Core\Entity\EntityEvents
+ * @see \Drupal\Core\Entity\EntityStorageBase::invokeHook()
  */
 class EntityEvent extends Event {
 
   /**
+   * The entity object.
+   *
    * @var \Drupal\Core\Entity\EntityInterface
    */
   protected $entity;
@@ -18,13 +23,17 @@ class EntityEvent extends Event {
    * EntityEvent constructor.
    *
    * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity object.
    */
   public function __construct(EntityInterface $entity) {
     $this->entity = $entity;
   }
 
   /**
+   * Returns the entity wrapped by this event.
+   *
    * @return \Drupal\Core\Entity\EntityInterface
+   *   The entity object.
    */
   public function getEntity() {
     return $this->entity;
diff --git a/core/lib/Drupal/Core/Entity/EntityEvents.php b/core/lib/Drupal/Core/Entity/EntityEvents.php
index aae0066..3c62b17 100644
--- a/core/lib/Drupal/Core/Entity/EntityEvents.php
+++ b/core/lib/Drupal/Core/Entity/EntityEvents.php
@@ -3,12 +3,33 @@
 namespace Drupal\Core\Entity;
 
 /**
- * @todo.
+ * Defines events for entity CRUD.
+ *
+ * @see \Drupal\Core\Entity\EntityEvent
+ * @see \Drupal\Core\Entity\EntityStorageBase::invokeHook()
  */
 final class EntityEvents {
 
   /**
-   * @todo.
+   * Maps entity hook names to event names.
+   *
+   * @var string[]
+   */
+  const HOOK_TO_EVENT_MAP = [
+    'create' => self::CREATE,
+    'presave' => self::PRESAVE,
+    'insert' => self::INSERT,
+    'update' => self::UPDATE,
+    'predelete' => self::PREDELETE,
+    'delete' => self::DELETE,
+  ];
+
+  /**
+   * Name of the event fired when creating an entity.
+   *
+   * This hook runs after a new entity object has just been instantiated.
+   *
+   * @see hook_entity_create()
    *
    * @Event
    *
@@ -17,48 +38,68 @@
   const CREATE = 'entity.create';
 
   /**
-   * @todo.
+   * Name of the event fired before an entity is created or updated.
+   *
+   * You can get the original entity object from $entity->original when it is an
+   * update of the entity.
+   *
+   * @see hook_entity_presave()
    *
    * @Event
    *
    * @var string
    */
-  const INSERT = 'entity.insert';
+  const PRESAVE = 'entity.presave';
 
   /**
-   * @todo.
+   * Name of the event fired after creating an entity.
+   *
+   * This event fires once the entity has been stored. Note that changes to the
+   * entity made by subscribers to the event will not be saved.
+   *
+   * @see hook_entity_insert()
    *
    * @Event
    *
    * @var string
    */
-  const UPDATE = 'entity.update';
+  const INSERT = 'entity.insert';
 
   /**
-   * @todo.
+   * Name of the event fired after updating an existing entity.
+   *
+   * This event fires once the entity has been stored. Note that changes to the
+   * entity made by subscribers to the event will not be saved. Get the original
+   * entity object from $entity->original.
+   *
+   * @see hook_entity_update()
    *
    * @Event
    *
    * @var string
    */
-  const PRESAVE = 'entity.presave';
+  const UPDATE = 'entity.update';
 
   /**
-   * @todo.
+   * Name of the event fired before deleting an entity.
+   *
+   * @see hook_entity_predelete()
    *
    * @Event
    *
    * @var string
    */
-  const DELETE = 'entity.delete';
+  const PREDELETE = 'entity.predelete';
 
   /**
-   * @todo.
+   * Name of the event fired after deleting an entity.
+   *
+   * @see hook_entity_delete()
    *
    * @Event
    *
    * @var string
    */
-  const PREDELETE = 'entity.predelete';
+  const DELETE = 'entity.delete';
 
 }
diff --git a/core/lib/Drupal/Core/Entity/EntityStorageBase.php b/core/lib/Drupal/Core/Entity/EntityStorageBase.php
index 06f3e2c..2173485 100644
--- a/core/lib/Drupal/Core/Entity/EntityStorageBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityStorageBase.php
@@ -168,14 +168,7 @@ protected function invokeHook($hook, EntityInterface $entity) {
     // Invoke the respective entity-level hook.
     $this->moduleHandler()->invokeAll('entity_' . $hook, array($entity));
 
-    $hook_to_event_map = [
-      'create' => EntityEvents::CREATE,
-      'insert' => EntityEvents::INSERT,
-      'update' => EntityEvents::UPDATE,
-      'presave' => EntityEvents::PRESAVE,
-      'delete' => EntityEvents::DELETE,
-      'predelete' => EntityEvents::PREDELETE,
-    ];
+    $hook_to_event_map = EntityEvents::HOOK_TO_EVENT_MAP;
     if (isset($hook_to_event_map[$hook])) {
       \Drupal::service('event_dispatcher')->dispatch($hook_to_event_map[$hook], new EntityEvent($entity));
     }