If visible is false or ignore is true the component won't be rendered.
If a component becomes ignored (its ignore attribute expression becomes true) the value the component is bound to will be deleted from the payload.
If a container component becomes ignored, its children values will be deleted too.
If the component is ignored or not enabled the validations won't apply.
And this component won't make form validations to fail.
If the component is not enabled and not visible, the component won't be rendered or validated, and the value it's bound too won't be deleted from payload.