Under the public access selection you have three options:
Private - only you or members in your project will be able to use and clone this app.
Public without Cloning - use this option when you want to showcase your app to the public but don't want to give away the "secret sauce". So when you share a link to the App or embed it on your website, users won't be able to clone it.
Public with Cloning - Users can both use and clone your app to make custom edits to their own instance of it. Before selecting this option, make sure that you do not have any sensitive data in your nodes configuration.
Guest Access
This allows you to share your app with specific permissions for specific emails.
Sharing Options
Shareable links should be used as a fast frictionless way to share your app with work colleagues and teammates
Embeds are used to add your app to an existing website
API is for more technical users that want to use the App endpoint in their development