How do I delete an iCloud backup?

In general, it is useful to create regular backups to iCloud and protect all of your data. But you won’t want to keep all your backups for life. When your iCloud storage is full, you will decide to delete old backups. Deleting iCloud backups is also a good practice to keep a better overview of your files. Often, you won’t really need these files anymore. But then, how do you delete a backup on iCloud?