Simply resolves whatever you type and accepts this as a claim value.
When deploying SharePoint with Federated Claims Authentication, the out of the box “People Picker” no longer searches your directory.
This functionality is “as designed” by Microsoft, where SharePoint no longer has a physical connection to your Active Directory. While this makes sense when federating with external organizations where you wouldn’t search their directories for users and groups, it doesn’t allow users to search the on-premise directory. In fact, many organizations deploy SharePoint with federated claims authentication with no intention of ever federating with external organizations. The Optimal People Picker/Claims Provider is a vendor supported Claims Provider that re-enables the search capability for SharePoint. This allows end users to confidently search for and select users and groups from their on-premise directory. The claims provider leverages the Virtual Identity Server, so the claims provider not only supports multiple AD forests; users can exist in any directory or database.