I am in the process of doing a factory reset on my lap top and wanted to Sync some of my previous data after.

When syncing 'Apps - The list of apps I've installed' with Onedrive after logging in with your Microsoft account, I was just wondering what is considered an 'app'? Is it just something I bought in the app store or is it anything I previously installed/downloaded on my computer? For example, if I downloaded Diablo 3, is that considered an app or is it a separate file that I should have backed up on a USB? Do I have to download all the apps again or with syncing, does it do it automatically?

But that's not what it means to everybody. As far as I'm concerned, "app" is simply short for "application," and "application is a word that essentially means the same thing as "program." So to me, all programs are "apps." What Microsoft means by "app" in this particular case, I have no idea. They have confused many people with their non-traditional use of the word, and they are inconsistent in its use.