you'll be downloading the installations filed which can be backed up to an external drive. i did this when I use to get the CD version because they can and do go bad. After 3 more tax years the download will no longer be available and you won't be able to reinstall from the backup drive. The same would be true if you had the CD because Turbotax stops supporting older versions of its software. for example 2019 can no longer be reinstalled. Even if you had 2019 installed on a second drive, you'll get an error message when trying to open it.
