What does Update Email in Advance notification page do ?

The description of this item is not clear. What is this setting for?...
settings > emails > notification 1 > advanced > update email - "While this
option is disabled, changes on the form will not affect the email content"
Thanks again for all your help.

When you add a field to your form it automatically populates the email with this info. If you disable this setting then when you add a field to your form, it wont automatically add it to the email. You would have to do it manually.

Its useful when you create a custom email notification/autoresponder template. Because a change on your form would overwrite your template.

It sounds like you're saying it controls whether or not, elements added in
form builder are automatically added as a field to settings > emails >
email > email content.
Is that correct? The wording next to the feature makes it sound like it's
talking about actual emails, instead of the email content feature.

Thank you

Yes that's right fields added in the form builder will not automatically be added to the email content if this setting is disabled.

Ok, thank you very much.