what is the purpose of form_state , delta variables in drupal

site given the delete description ,

sorry but am not understand clearly,

i开发者_如何学编程s it possible to explain with some example..

The delta variable is used several places in drupal to know which is which.

In this case with hook_block, it is possible to define more than one block. Drupal uses the delta to know what block it is currently processing.

$form_state is something Drupal uses to store data related to forms. Primarily the values submitted, but it can also be used for other things.