unclear distinction between #type "hidden" and "value"

API page: https://api.drupal.org/api/drupal/developer%21topics%21forms_api_referen...

lost 2 days on the FAPI

finally discovered that stored data in as a #type "hidden" means i get the data back in my $form_state['input'] on repeat calls to myform_form()

putting data in as a #type "value" does not send the data back in $form_state - presumably (haven't looked) its post in the form so available to js (???)

anyhoo.... seems like the distinction between

form_state['storage'] (which i couldnt get to return at all for some reason)

and a form element #type "hidden" and "value" could be clarified...

love all your work

please dont rush with drupal 8 :-)