“Private” presentations can only be viewed by you or other people that you explicitly invite to view or edit them. People you invite must confirm their email before they can view or edit your presentation. You can rescind viewing permissions for other people at any time.
“Public” presentations can be viewed by anyone with the public link or embedded on a website or blog. By default, public presentations are not indexed by search engines like Google unless you embed the public link on a website or blog or post the public link to a social sharing site like Facebook or Twitter.
We recommend keeping your presentations set to Private for confidential information. This means that even if someone has a direct link to your presentation, they will not be able to view it if you have not given them permission via email invitation.
To change your privacy setting, click on Share and toggle between Public and Private.