Are Not Visible Items actually on the page?

Targets Web
#1

When I put control on a page (Say a WebButton).

And the button is set visible=false

Does the button acutely get set to the page and lives there invisibly?

Or does the server simply not send it at all?

#2

All controls are sent to the page, regardless of visibility. Visibility just determines whether or not the user can see it.

#3