Why should i use [EntityFieldQuery][1] when i can do the same work with [Db_select()][2] to fetch the value.

It would be better if anyone cal provide an example not a link.


  [1]: https://api.drupal.org/api/drupal/includes!entity.inc/class/EntityFieldQuery/7
  [2]: https://api.drupal.org/api/drupal/includes!database!database.inc/function/db_select/7