My new WD Passport created two duplicate backups

While creating a complete backup of my PC, my PC went in sleep mode. When I clicked it back, the WD screen stated something like, “failure to complete back up.” So a started a new backup, which successfully completed.

However, when I looked at my files, I saw there were two completed backups that appear identical.
With each being almost 0.8 T, that is a lot of wasted space in a 4T hard drive.
How do I delete one of the duplicates?
When I begin to backup new files, will these newer files be backed up in both identical backups?

Thank you to anyone who can help.