Archived backup files are backup files that have lost their backup instance. This is due to the deletion of a backup instance or deletion of Web Application or Database. These archived backup files can be downloaded and restored like a normal backup file.
When you click restore backup, you need to choose which Web Application/Database this backup files will be deployed. You can deploy your backup to any Web Application/Database in any server that you own.
If the backup file is a Web Application backup, restoring backup files will overwrite your files inside the Web Application if it already exists.
if the backup file is a Database backup, please make sure the selected database is empty before restoring your backup. If it isn't, please be sure that you know what you are doing.