In Backlink Analysis you'll see your Actioned v. Unactioned links. If you click on a segment, it'll update your link results below to show the associated links.
If you add a link to either Keep OR Remove List, this is classified as an Action.
We've chosen to keep this decision binary to make your backlink auditing more efficient. Either you'd like to keep a link on your backlink profile, or you want to remove it, and when working on a profile you can now see any links that haven't been decided on.
You can add links to multiple lists. For example, you would have your Disavowed links in your Remove List, and the links you want to monitor in your Monitor List and either Keep or Remove depending on why you're monitoring it.