Claim Types are explained in more detail in the [Claim Types] documentation.
You should now see a success dialogue informing you that your claim has been added, and your new claim should now appear in the Additional Details list.
You can choose to edit or delete any claim from this Additional Details tab. Click the pencil icon to edit the claim, or the delete icon to remove the claim entirely from this user.
Editing the claim will turn the field into a writeable text-box that will allow you to change the name of the claim:
Choosing to delete the claim will immediately remove the claim entirely from the user's claim list.